diff --git a/README.md b/README.md
index b3a419c..09c2f27 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # relatives-tree
 
-A tiny library (~3.02 KB gz) for calculating specific JSON data to family tree nodes and connectors.
+A tiny library (~3.01 KB gz) for calculating specific JSON data to family tree nodes and connectors.
 
 🖥 [Here is a demo](https://sanichkotikov.github.io/react-family-tree-example/) app with React rendering.
 
diff --git a/src/connectors/children.ts b/src/connectors/children.ts
index 784e0d6..4b44abc 100644
--- a/src/connectors/children.ts
+++ b/src/connectors/children.ts
@@ -1,67 +1,63 @@
+import { getParentsX, withType } from '../utils/family';
 import { getUnitX, nodeCount, nodeIds } from '../utils/units';
-import { withType } from '../utils/family';
-import { inAscOrder, max, min, withId } from '../utils';
-import { SIZE } from '../constants';
-import { Connector, Family, FamilyType } from '../types';
+import { inAscOrder, max, min, withId, withIds } from '../utils';
+import { HALF_SIZE, NODES_IN_COUPLE, SIZE } from '../constants';
+import { Connector, Family, FamilyType, Unit } from '../types';
 
-// TODO refactor
-export const children = (families: Family[]): Connector[] => {
-  const connectors: Connector[] = [];
+export const children = (families: readonly Family[]): readonly Connector[] => (
+  families
+    .filter(withType(FamilyType.root, FamilyType.child))
+    .reduce<Connector[]>((connectors, family) => {
+      const parent: Unit | undefined = family.parents[0];
 
-  families.filter(withType(FamilyType.root, FamilyType.child)).forEach(family => {
-    let pX = 0;
-    const mY = family.Y + (family.parents.length ? SIZE : 0);
-
-    if (family.parents.length === 1) {
-      const pUnit = family.parents[0];
-      pX = getUnitX(family, pUnit) + nodeCount(pUnit); // TODO
+      const pX = getParentsX(family, parent);
+      const mY = family.Y + (parent ? SIZE : 0);
 
       // from parent(s) to child
-      if (pUnit.nodes.every(node => !!node.children.length)) {
-        const pY = family.Y + 1;
+      if (parent && parent.nodes.every(node => !!node.children.length)) {
+        const pY = family.Y + HALF_SIZE;
         connectors.push([pX, pY, pX, mY]);
       }
-    }
 
-    const parentIds = family.parents.map(nodeIds).flat();
+      const parentIds = family.parents.map(nodeIds).flat();
+      const positions: number[] = [];
 
-    const cXs: number[] = [];
+      family.children.forEach(unit => {
+        const left = getUnitX(family, unit) + HALF_SIZE;
 
-    family.children.forEach(cUnit => {
-      const cX = getUnitX(family, cUnit) + 1;
+        // from child to parent(s)
+        unit.nodes.forEach((node, index) => {
+          if (node.parents.some(withIds(parentIds))) {
+            const nX = left + (index * SIZE);
+            positions.push(nX);
+            connectors.push([nX, mY, nX, mY + HALF_SIZE]);
+          }
+        });
 
-      // from child to parent(s)
-      cUnit.nodes.forEach((node, index) => {
-        if (node.parents.find(rel => parentIds.indexOf(rel.id) !== -1)) {
-          const nX = cX + (index * 2);
-          cXs.push(nX);
-          connectors.push([nX, mY, nX, mY + 1]);
+        // between child and child's spouse
+        if (nodeCount(unit) === NODES_IN_COUPLE) {
+          connectors.push([left, mY + HALF_SIZE, left + SIZE, mY + HALF_SIZE]);
         }
-      });
 
-      // between child and child's spouse
-      if (nodeCount(cUnit) === 2) {
-        connectors.push([cX, mY + 1, cX + 2, mY + 1]);
-      }
-      else if (nodeCount(cUnit) === 1 && cUnit.nodes[0].spouses.length) {
-        family.children.forEach(nUnit => {
-          if (nUnit.nodes.findIndex(withId(cUnit.nodes[0].spouses[0].id)) !== -1) {
-            const xX = [cX, getUnitX(family, nUnit) + 1].sort(inAscOrder);
-            connectors.push([xX[0], mY + 1, xX[1], mY + 1]);
-          }
-        });
-      }
-    });
+        // between child and child's side spouse
+        else if (nodeCount(unit) === 1 && unit.nodes[0].spouses.length) {
+          family.children.forEach(nUnit => {
+            if (nUnit.nodes.some(withId(unit.nodes[0].spouses[0].id))) {
+              const xX = [left, getUnitX(family, nUnit) + HALF_SIZE].sort(inAscOrder);
+              connectors.push([xX[0], mY + HALF_SIZE, xX[1], mY + HALF_SIZE]);
+            }
+          });
+        }
+      });
 
-    if (cXs.length > 1) {
       // horizontal above children
-      connectors.push([min(cXs), mY, max(cXs), mY]);
-    }
-    else if (cXs.length === 1 && pX !== cXs[0]) {
+      if (positions.length > 1)
+        connectors.push([min(positions), mY, max(positions), mY]);
+
       // horizontal between parent(s) and child
-      connectors.push([Math.min(pX, cXs[0]), mY, Math.max(pX, cXs[0]), mY]);
-    }
-  });
+      else if (positions.length === 1 && pX !== positions[0])
+        connectors.push([Math.min(pX, positions[0]), mY, Math.max(pX, positions[0]), mY]);
 
-  return connectors;
-};
+      return connectors;
+    }, [])
+);
diff --git a/src/connectors/middle.ts b/src/connectors/middle.ts
index 082e20c..c8d51b2 100644
--- a/src/connectors/middle.ts
+++ b/src/connectors/middle.ts
@@ -1,7 +1,7 @@
 import { inAscOrder, withId } from '../utils';
 import { getUnitX, nodeCount } from '../utils/units';
 import { withType } from '../utils/family';
-import { HALF_SIZE, SIZE } from '../constants';
+import { HALF_SIZE, NODES_IN_COUPLE, SIZE } from '../constants';
 import { Connector, Family, FamilyType, Unit } from '../types';
 
 const calcConnectors = (family: Family, families: readonly Family[]) => (
@@ -9,7 +9,7 @@ const calcConnectors = (family: Family, families: readonly Family[]) => (
     const pX = getUnitX(family, unit) + HALF_SIZE;
     const pY = family.Y + HALF_SIZE;
 
-    if (nodeCount(unit) === 2) {
+    if (nodeCount(unit) === NODES_IN_COUPLE) {
       connectors.push([pX, pY, pX + SIZE, pY]);
     }
     // TODO: update and refactor
diff --git a/src/connectors/parents.ts b/src/connectors/parents.ts
index 96c2816..4c4c93f 100644
--- a/src/connectors/parents.ts
+++ b/src/connectors/parents.ts
@@ -1,7 +1,7 @@
 import { prop, withIds } from '../utils';
 import { getUnitX, nodeCount } from '../utils/units';
-import { withType } from '../utils/family';
-import { HALF_SIZE, SIZE } from '../constants';
+import { getParentsX, withType } from '../utils/family';
+import { HALF_SIZE, NODES_IN_COUPLE, SIZE } from '../constants';
 import { Connector, Family, FamilyType, Unit } from '../types';
 
 const getChildIDs = (unit: Unit): readonly string[] => (
@@ -10,12 +10,12 @@ const getChildIDs = (unit: Unit): readonly string[] => (
 
 const calcConnectors = (family: Family) => (
   (connectors: Connector[], unit: Unit) => {
-    const pX = getUnitX(family, unit) + nodeCount(unit);
+    const pX = getParentsX(family, unit);
     const pY = family.Y + HALF_SIZE;
     const mY = family.Y + SIZE;
 
     // between parents
-    if (nodeCount(unit) === 2) connectors.push([pX - HALF_SIZE, pY, pX + HALF_SIZE, pY]);
+    if (nodeCount(unit) === NODES_IN_COUPLE) connectors.push([pX - HALF_SIZE, pY, pX + HALF_SIZE, pY]);
     // from parent(s) to child
     connectors.push([pX, pY, pX, mY]);
 
diff --git a/src/constants.ts b/src/constants.ts
index b2884f8..f771914 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -1,2 +1,4 @@
 export const SIZE = 2;
 export const HALF_SIZE = SIZE / 2;
+
+export const NODES_IN_COUPLE = 2;
diff --git a/src/middle/create.ts b/src/middle/create.ts
index 4ec08c6..306a308 100644
--- a/src/middle/create.ts
+++ b/src/middle/create.ts
@@ -6,6 +6,7 @@ import { setDefaultUnitShift } from '../utils/setDefaultUnitShift';
 import { prop, withRelType } from '../utils';
 import { newFamily } from '../utils/family';
 import { unitsToNodes } from '../utils/units';
+import { NODES_IN_COUPLE } from '../constants';
 import { Family, FamilyType, Node, RelType } from '../types';
 import { correctOverlaps } from './correctOverlaps';
 
@@ -39,7 +40,7 @@ export const createBloodFamilies = (store: Store): readonly Family[] => {
   const mainFamily = createFamily(store.root.parents.map(prop('id')), FamilyType.root, true);
   const parents = unitsToNodes(mainFamily.parents);
 
-  if (parents.length === 2) {
+  if (parents.length === NODES_IN_COUPLE) {
     const { left, right } = getSpouseNodesFunc(store)(parents);
 
     return [
diff --git a/src/store.ts b/src/store.ts
index 31b959e..a5edebb 100644
--- a/src/store.ts
+++ b/src/store.ts
@@ -2,6 +2,7 @@ import { toMap, withId } from './utils';
 import { withType } from './utils/family';
 import { Family, FamilyType, Node } from './types';
 
+// TODO think about refactoring
 class Store {
 
   private nextId: number;
diff --git a/src/utils/family.ts b/src/utils/family.ts
index 65282ff..4b982a4 100644
--- a/src/utils/family.ts
+++ b/src/utils/family.ts
@@ -1,7 +1,7 @@
 import { SIZE } from '../constants';
 import { Family, FamilyType, Unit } from '../types';
 import { max } from './index';
-import { nodeCount, rightSide } from './units';
+import { getUnitX, nodeCount, rightSide } from './units';
 
 export const newFamily = (id: number, type: FamilyType, main = false): Family => ({
   id,
@@ -23,3 +23,7 @@ export const heightOf = (family: Family): number => [
 export const rightOf = (family: Family): number => family.X + widthOf(family);
 export const bottomOf = (family: Family) => family.Y + heightOf(family);
 export const unitNodesCount = (units: readonly Unit[]): number => units.reduce((acc, b) => acc + nodeCount(b), 0);
+
+export const getParentsX = (family: Family, unit: Unit | undefined): number => {
+  return unit ? getUnitX(family, unit) + nodeCount(unit) : 0;
+};
diff --git a/src/utils/getExtendedNodes.ts b/src/utils/getExtendedNodes.ts
index f364b6c..9f547f5 100644
--- a/src/utils/getExtendedNodes.ts
+++ b/src/utils/getExtendedNodes.ts
@@ -1,13 +1,14 @@
 import { getUnitX } from './units';
 import { hasHiddenRelatives } from './hasHiddenRelatives';
+import { SIZE } from '../constants';
 import { ExtNode, Family, FamilyType, Node, Unit } from '../types';
 
 const extendNode = (family: Family) => (
   (unit: Unit) => (
     unit.nodes.map((node: Node, idx: number) => ({
       ...node,
-      top: family.Y + (unit.child && !!family.parents.length ? 2 : 0),
-      left: getUnitX(family, unit) + (idx * 2),
+      top: family.Y + (unit.child && !!family.parents.length ? SIZE : 0),
+      left: getUnitX(family, unit) + (idx * SIZE),
       hasSubTree: hasHiddenRelatives(family, node),
     }))
   )
diff --git a/src/utils/getSpouseNodesFunc.ts b/src/utils/getSpouseNodesFunc.ts
index 8fb6cf8..52da5af 100644
--- a/src/utils/getSpouseNodesFunc.ts
+++ b/src/utils/getSpouseNodesFunc.ts
@@ -1,9 +1,8 @@
 import Store from '../store';
+import { NODES_IN_COUPLE } from '../constants';
 import { Node, Relation, RelType } from '../types';
 import { byGender, relToNode, withRelType } from './index';
 
-const NODES_IN_COUPLE = 2;
-
 type SpousesNodes = {
   left: readonly Node[];
   middle: readonly Node[];