The most important for A now is to take care of herself and baby

physically. I suggest you help hiring somebody to cook for A and helping taking care of the baby, several hours per day, at least. If A does not have money, you can pay in front and ask A to write a borrowing note. Don't be afraid of spending money now. I suggest hiring an American Doula (or a good American nanny, http://www.dona.org/). (They are much more expensive, but B and B's mom are less likely to quarrel with them. So A can be taken care of.)

Talking about divorce when A is recovered.