If you have a grate in the breeder box, I would take her out because once the babies can swim well, they can just go up the grate right into the mommy's jaws. If you have another tank I would recommend putting her in there by herself; I've heard that if you put a livebearer back in it's tank with other fish right after it's given birth, the other fish might bother it and it might weaken it and die.