Hello. I recently had one of my Black Mollies give birth to about 6 babies.
The best solution to keep the babies alive is probably a breeder's net. A breeder's net is a tight-woven net put around a plastic frame that hangs inside of your tank with the babies inside, so they're protected from their parents. I bought one at PetSmart for about $5.00.
Okay, so, once you have bought the breeder's net, you will need to assemble it if it isn't already assembled. Once the net is put together, hang it on the inside of your tank. Then (you may need someone to help you with this), hold the breeder's trap down while holding the lid up, and scoop up the baby/babies in another net. Then just put them inside the breeder's net, and close the lid. It's that simple.
Feeding: Your baby/babies should be fed two or three times a day at minimum. I started off with three times a day but after a while my baby managed fine with only two feeding times a day. Your babies will eat the food you feed all your other fish, but before you put it into the net for them to eat, you will need to grind the food into a powder, almost.
Get a paper plate, put some fish food on it, and grind the food with a metal spoon for a few minutes. Once the food is nearly made into a powder, pinch some of the food, and feed your babies.
I tried these strategies and they worked. Just make sure you don't put too much food into the net, or it will rot and eventually kill the baby inside.
Let me know if you need any more help!!!