Mother & Daughter pregnant

Question
Cats were in heat about 2 weeks apart, can feel kitten movement in older gestation (mother.)  Mom hisses at daughter when she comes near.  Need we be concerned about keeping them separated after birth?  Mom is very independent, but loving when she wants to be, daughter is warm and fuzzy, loving and laid back.  This will be mom's 2nd litter.

Answer
I would try to keep the litters separated once they arrive. It might not be necessary to keep the Mother away from daughter's litter and pregnancy, but since mom seems a little more stand-offish, I would simply suggest setting up two different kittening boxes in two different rooms for the cats.

It seems like you have a good idea of what needs to be done, so good luck!