That makes a hell lot of sense, and i think it's mostly about option A.
I've always been sweet in the relationship, she trust me and i would never harm her. But she seems like a person, that needs comfort and confirmation from guys. I gave her that, but slightly as her "confirmation" was filled, she needed to get it from other guys.
Her best friend also told me, that she was in a relationship with a guy. About three months and then she started flirting with a co-worker, and a bartender. She ended the relationship so she could be schrew the bartender a couple of times. Suddenly the bartender wasn't interested in her anymore and she had no one to get comfort from. Then she met me and yeah, you know the story.
I did not know anything about her before, but i never saw her as that type. She was so comitted in the beginning, and when i told about Malta, she instant looked at plane-tickets to come visit me. That behaviour almost scared me, but also gave me an indication, that she really wanted to be with me, no matter what! - So i never saw her as some "maneater"
That's why it schocked me, when i heard she made out with another guy, the same day she told me, that she needed more time. I rather wanted her to tell me, that it was completely over instead of leaving me with hope. Well FUCK HER!
And to the question about 23 and school. No, it's not late

- It's not school/school but my journalist-education
