A molly fry is a pretty good size. They need lots of finely crushed food but do not need things such as egg yolk. It wouldn't hurt them but that is generally a food for smaller fry. If you have any, a crushed up bit of spirulina flake goes over well with molly fry. Mollies need a diet rich in vegetable matter and spirulina flake is a decent source of it for them. I use the spirulina for my adults and always add some for the fry along with regular flake.