Were they all children?

In her mind, all but Vicky seemed to be young.



I'd say this cloud is Cumulo Nimbus.
Didn't he discover America?
Penfold, shush.

We don't know at what age the abuse and torture started but if it was at 3 or 4 then you can imagine why all the personalities were that age.

I think the book gave Vicky's age as about 13 (although she seemed a rather mature 13!) down to Ruthie, one of the less-developed selves who was about 2 or 3--the age Sybil would've started developing some sense of self and early memories.