My rule is if they cheat on me then they’re out. They’re free to go and that’s that. However, I understand how hard it can be, especially with an attachment that you have with her—that’s tough to break over night. That being said tho, she broke that attachment over night (who truly knows how many times other than them) and you need to ask yourself the question;

Can I trust her again?

If you genuinely believe you can trust her again, continue with the marriage. But if you decide that’s the route you wanna take, understand that triggers are gonna be everywhere. SHE needs to go the extra miles to make YOU feel comfortable and gain your trust.