OK, I am about to boo hoo now, my son and his wife are getting rid of the 3 bigger cats. Caesar, Cammy and Patty. I made it clear to them I did not want them in a animal shelter where they will be put down. They are worried Caesar who is around 9 years old and just stays on the couch in the living room sleeping or under the couch will get in the baby bed. The two female sisters would be more likely to do that. They are going to try and find them good homes first. Our Collierville Animal Shelter is a no kill shelter, as is they say the Bartlett Animal Shelter. I do not believe that. Anyway, I wish some of the cat lovers on this forum site were closer that could take them. Caesar is the calmest cat. And Cammy and Patty are going to be highly upset that they will no longer be with their human mommy and daddy they have known for almost a year. Do cats remember certain people that long??? I am sad! 
The kittens are more adoptable. Period. Good luck finding homes for the older ones, especially if they are not spayed/neutered. Grown cats are hard to place, as they are harder to adapt and assimilate into new households.
It is not a big deal to keep cats out of the crib. I had 2 indoor cats when Will was born, and 3 when Kate came along. Yeah, every now and then, I would find one curled up in her bed. So what? At night we closed the door to her room.
As long as the cats are neutered/spayed, vaccinated, flea-free, and your DIL is not changing the litterbox while pregnant, they should be fine. But they have too many cats, so finding new homes for the kittens should help.