I confirmed the "alibi" with her M. Not directly, but indirectly. Also, she was only gone for 2 hours - I struggle to think she was meeting up with someone. I guess it's possible, but it doesn't seem very logical.
Believe what you want... I am telling you the reality. I think you know deep down inside what that little voice is telling you. You most certainly thought the same thing or you wouldn't have needed to confirm it with her mother...
I know that my mother would cover for me anytime anyplace if I asked her to....
I think you are in denial.. This was not the ONLY red flag I have observed reading your situation.. Just the most OBVIOUS one...
Your choice to believe what you want. I want you to know that you are not doing yourself any favors by denying the obvious.