We have three cats and a dog.
The future nursery is currently the "cat room," where their food is located, so I imagine they'll go in there. They have all been around children at some point. Anchovy is getting older and will not be able to jump into the crib unless there is something lower next to it -- easily solved. Extra ignores children so I don't see it being a problem. Tolstoy, however, is very curious and very nimble. However, he is incredibly sweet and tolerates pretty much any behavior (he's had his tail pulled, been carried around by very young kids, and he just walks away) so I don't see it ever being a problem.
Otherwise, we'll just put a baby gate at the door, because he refuses to jump over them.