something i'd like to add: when my acei was holding, i was late home from school, and when i cam, the other fish were like chasing and bullying the female who was lying on the bottom of the tank about to give birth. it was pretty brutal. we lost a lot of fry because of that, and subsequently (after birth) we moved her back to the big tank, and because she was still so weak, she died due to stress (or so i think). it was a bad move. when my acei first gave birth, i was still a complete newbie at mbuna breeding. in fact, i put all 30 fry into an uncycled 10 gallon tank. 28 of them survived. i think you will be fine if you put the fry into the 55 gallon tank. i dont know about the female though.
just my two cents. you'd probably better off if you listened to Tazman though, he is more experienced.
29 gallon freshwater tank - b/n catfish, neon tetras, and 4 gouramis
60 gallon Lake Malawi tank - under construction