If I were you here is what I would do. For the first week or so, until the dogs get use to each other and the baby gets use to the idea of sleeping else where, I would stick the new baby in a box just big enough that she won't jump out of (or a laundry basket would probably work). That way you don't have to buy another crate. Then after the dogs are use to each other and the baby knows to sleep at night I would stick them together. The pup will probably be use to sleeping with it's litter mates anyway. I know my dogs like to snuggle at night time. Of course mine all snuggle with me in my bed.
