La1serg

let x = [{name: 'вася', parents: []}, {name: 'петя', parents: []}];
let y = x.map((el, i) => ({name: el.name, number: i+1}))

const getChunks = (arr, chunkSize) =>
  Array.from(
    { length: Math.ceil(arr.length / chunkSize) },
    (n, i) => arr.slice(i * chunkSize, (i + 1) * chunkSize)
  );

// или

const getChunks = (arr, chunkSize) =>
  arr.reduce((acc, n, i) => (
    i = i / chunkSize | 0,
    (acc[i] = acc[i] || []).push(n),
    acc
  ), []);

// или

const getChunks = (arr, chunkSize) =>
  arr.reduce((acc, n, i) => (
    (i % chunkSize) || acc.push([]),
    acc[acc.length - 1].push(n),
    acc
  ), []);

const arr = [...Array(50).keys()];
const chunks = getChunks(arr, 7);