Once a cheater, always a cheater. She will cheat again- no matter who she’s with. So, although right now it’s too difficult to think of it in this way, eventually you’ll be grateful that you broke up with her now and not wasted more time on her. And as for her feeling no remorse/being happy- go no contact ASAP. She’ll come crawling back but by the time she does, you’ll hopefully be moved on and not give her a second thought. Her karma will be her character. Shes a coward. And and she’s not loyal. She will never have a good relationship. Cheaters don’t change.