As far as I know there are no cichlids, that will be happy in a 2 or a 5 gallon tank. You could probably put ONE shelldweller in a 5 gallon but I would not recommend it.
Molly fry, LOL.. Why don't you take them into the LFS for store credit ? or grow them out and sell them on Aquabid. this is much more "humane" than the previously stated method.
If you would like to keep cichlids, to eat fry or otherwise, I recommend at least a 33 gallon tank, for small Tanganykans, or at least a 55 for Malawi (mbunas) With cichlids, the larger the tank, the better
One more thing - if you have never kept cichlids before, please do not start keeping cichlids for the only reason to eat baby fry