Hello.Sorry that I reply almost one year after!I just wondered,how the back of children's head,was?
In LYRA and first Geobra children,if hair was removed,the figure was being damaged!It was also happened in some victorian children's hair.At first in boys with black hair and in boys and girls with brown hair,then only in some boys with brown hair!
For the most of the children figures I have,back of their head without hair is:

I think in new children figures hair is stuck with head and they cannot be removed!Have you ever tried to remove hair from new children figures?