Should I give her a last chance?

well, I had a girlfriend (for 2.6 years) which I thought we were at our best, suddenly she asked me for a time because because we had some trouble with my mother, she continued flirting and kissing me although I asked once to respect the agreement we made ( it was our first semester at college so we had a lot of parties comming from nowhere)
after a month we went for a coffee and continued dating but as friends, after the second month she asked me out for a date (which was grate ) and asked me if I could be her boyfriend again (I said yes). everything was great we were dating, going to each other classes until one day I felt we were affecting our school grades I decided I check her WhatsApp but before that I asked her for a time until summer (which wasn't much), I found out she kissed a guy really really drunk and saying she enjoyed it and that she didn't regreat nothing after a week we asked me to be her boyfriend. a days after she liked for me but I tell her I didn't want to know nothing of her, i agreed to listen to her and she told me she did it but she kept teling it was good because she wanted to be cool to her new friends, she stills sending me msgs and going to my school.
should I give her another opportunity?
Should I give her a last chance?
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