How many times do you feed a female Betta fish?
Feed her 3-4 times a day, 2 pelets in the morning and 2 pelets at night
Stop feeding them so much. Your female sounds like she has bloat. only feed them 2-3 pellets per day, for 6 days a week. the 7th day they need to fast. Dont feed your female until her belly goes down. Go to bettafish.com to get more indepth information from betta fish breeders and experts who can better asses what killed your male and help you care for your female better.