If you can, drop down some zucchini. Chances are they are eating any left overs that are chilling in the bottom of the tank - if the betta doesn't eat it
Some signs of the betta eating more than he should is a big belly. I've had a female do that.
Breed for the breed, not for the money; the words any REAL breeder would understand.
You must know nothing in order to know all, for all is nothing and nothing is for all.