First, bettas shouldnt be kept in bowls.
Breeding bettas requires research so you know what to do. Basically, youll need a larger tank, with a divider. Male on one side, female on the other. Feed them bloodworms and other live/frozen foods for two weeks or so. When the female has vertical stripes and the male builds a nest, remove the divider. As soon as the eggs are laid, remove the female, because the male will kill her. And once the babies are swimming on their own, remove the male.
Female bettas can usually be housed together just fine. Male bettas CANNOT be housed with any other betta.