I am with you on not putting 10 year olds out of the house. They will not understand why they are out there... to many things can happen to them outside.

First thing she needs to do is keep them apart as much as possiable. Do not force the kitties on the baby and do not force the baby on them. Something is going on and she will just have to watch really close to see what it is but keeping them apart seems like what needs to be done right now. Give the kitties a "safe zone" they can go to where they know no one will bother them and make sure they have free access to it at all times.

Amy has her kennel and she knows when she is in there, NO hand is allowed to reach in there, nothing will bother her in there and that is where she runs when little kids come in that scare her. They are not allowed to go near her in there so she can feel safe. Give the kitties a safety zone to go to when they are afraid where nobody can mess with them, and be consistant.