NO. DON'T. Goldfish are coldwater and mollies prefer at least 3 of their own kind. If you'd like, you could try three mollies, three swordtails/platys or three guppies (One male + 2 female) with the female bettas, but NO GOLDFISH please.
Anyways, Im 13, and I have a 10 g. quarantine, 30 g...