Mollies aren't known to eat the fry, but alot times the first time mom does. So bottom plants and top plants are good. The fry will swim to the bottom first day then to the top for the next week. They are atrackted to the light and are top swimming fish. I don't know what else is in your tank, but if they don't get ate or go threw a temp swing 95% sould grow till adulthood.