you can leave the babies with the adults for at least a cuple of weeks after they are swimming around. Normally they get removed when the adults no longer try to herd them up and keep them in a group. Then the fry swim off on their own and either get eaten or survive and grow into adults.
You can feed them on newly hatched brineshrimp (nauplii), microworms and very fine powder or flake foods that sink to the bottom. Brineshrimp nauplii is the best food but whatever you have is fine.