Question

This is the (children's childrens') room
These are the (boy's boys') families
My (son's sons' ) names are Ben and Tom
Look at the (womens' women's)hats
This is my (sister's sisters') daughter
Do you know the (mans' man's) name.

Answer 1

This is the children's room. 

These are the boys' families.

My sons' names are Ben and Tom.

Look at the women's hats!

This is my sister's daughter.

Do you know the man's name?