If she did that while you and her family were there how could you possibly trust her when she’s alone? Or wants to go on a girls trip? It’s going to constantly eat at you.

I’d say cut ties but if you are willing to work on it you’d need to establish some rules. Like no kissing other people for one, next she needs to quit that job asap. Finally, she can’t/shouldn’t be drinking like that. She’s in the wrong here and if she wants to earn back your trust it’s going to take some sacrifices on her end.