Search Results: boyfriend acting weird

When I started at my current job at the beginning of the year, I fell hard for a girl who I worked with. She spent a whole shift with me and we got to know each other very well. But I unfortunately discovered not only did she have a boyfriend, she's 17 and I am 22.
I felt we had a mutual flirtation going on for a while because my coworkers would mention it to me. But I backed off because of her age, mainly.
Since, we had a period of time we didn't say anything to the other at work because she was acting different. Once she got back from vacation, she constantly would try to jump into any conversation I had with anyone, and started to ask me to help in her area more and more.
She would ask me about minor issues with her boyfriend, and i thought it was very strange. But a month or so ago, a customer made a comment that I looked 35, and I honestly got a little self conscious. So I asked the girl how old I looked, and she snapped on me. She asked why she cares how old I am. I said I just was curious because of what the customer said. She went in and on how my age doesn't matter, and that she had a boyfriend and just kept rambling. Even her co-worker looked at me Wondering why she was snapping at me like that.
I left and I haven't spoken to her unless it was about work. She keeps making eye contact with me when I have to walk past her area, and then I'll go an alternative route to avoid her.
She even came out of an office after collecting a prize, and I was the only person there, she made a comment about the prize, and looked over at me, and I didn't look up or say anything and she left. Recently she's seemed bothered by me not saying hi to her and even once got mad at me for not saying hi to her.
Like? I'm keeping it professional, but this is weird.