I only know for sure that one of the rehabbers immediately released everyone but the mamma who had given birth. There is always a danger with mammals that a male will kill babies in order to send the female back into heat, so he can do it again --most especially if these did not happen to be his babies. ( Ask any urban police officer about how this is true even in humans. It's called the boyfriend syndrome.

)
Mamma squirrels will also become very protective and territorial once the babies are born, so it's imperative that whoever gives birth gets her own apartment.