No. Mollies themselves are too big for breeders really, so two in there is going to be quite stressful. I'd take them out. If you're worried about saving fry, put some floating plants in the tank. The fry will hide in those, and if you want to put them in the breeder net after they are born, that's fine. I'd look into getting a fry tank, if you're serious about Molly breeding.