Status: In A Relationship

So I have liked this girl for a long time, actually, she liked me for as long about as we've known each other (so about 7 years). It's an irrelevant story why we didn't do anything.

I moved 5 hours away from her 3 years ago, and she acted like she liked me more than she did when I lived there up until this summer.. Well I finally got fed up with standing around (and got a confidence boost since she acted like she like me) so I started to flirt with her. She acted like she didn't want anything to do with me. I've been confused for a while why that happened because she is the best friend I've ever had and it is completely opposite of her to ignore someone. I didn't say anything rude or stupid just things like, "I like your new profile picture". I didn't get a chance to say anything really because she just ignored me.

Well I finally found out why she ignored me. She has never had a boyfriend, she has made it 17 years being single and right when I tried to move things with her someone else was trying the same thing. Now she is in a relationship. I can't blame her, I don't live close to her anymore and we haven't talked in a while. Whoever this dude is, made a move before me and if she had to choose between two people, why the hell would she choose someone who lives 5 hours away?

Here is my question. Although I'm not going to put my life on hold because of her, how do I get her to notice me? I haven't had a chance to catch up with her in a long time, but I'll be spending the week with her and some people from my church soon. I don't want to look like a desperate fool and ruin any potential chances later with her. So because I'll be in a situation where I have to interact with her, how should I do this? How do I catch up with her? I can't do anything if we don't even talk.

Oh, there is also a good chance I'll move back within the next 1-2 years.