Glad to hear that. I think my sister can be a better person but she would need a new guy. Her bf is probably never going to get over it so she can't be a better gf to him, even if she's really remorseful.
It doesn't sound like her bf totally forgave her. I think if someone takes back their partner that cheated, then at some point they can't continue throwing it in their face. At some point, they have to accept and forgive.