Question

What is the possesive form of children

Answer 1

So, a possessive noun is usually used to indicate who or what has something, like "The Dogs' ball."
To change this form of children,plural, to a possessive noun, you will want to add an apostrophe, and then an s. It changes to this:

Children's

Answer 2

The possesive noun is children's because possesive means add an apostrope s