So heres the story.
Sorry in advance for any bad punctuation,spelling and grammar errors. Im in a bit of a hurry.

I've been dating this girl for the past 8 months. When I met her She was living with her grandparents while she went to school, during this time I learned, among other things that she was given up for adoption at a young age, and ended up in and out of foster care until the age of 18, then she basicly moved around for awhile on her own until her grandparents ended up taking her in for a summer. But after she graduated from her trade school, they kicked her out and all but completely cut off communication with her. her plan was to move 4 hours away with a friend with the money she had made working over the summer. At this point we had been dating for about 3 months and i really didnt want the relationship to end, and didnt consider driving back and forth to be an option since she does not drive and long distance relationships havent worked out for me in the past. (she hadn't been able to aquire a drivers liscence due to her unstable living situations). So i asked her to try and find a place here, she agreed and in the mean time while she was searching for an apartment she stayed with me and my family. It got rough for awhile as we adjusted living together for about a month and I became responsible for getting her back and forth from the places she needed to go.
Since then she's gotten her own appartment and a job very near by.
However over the last few months we've been off and on repeatedly breaking up and making up. We've tried and tried to work through our issues, but it seems we might just be too different. we just recently broke up again, but have agreed to try and stay friends. At this point im starting to feel like its time to move on to something new. Problem is (no surprise) now she want to try again...JUST IN TIME FOR THE HOLIDAYS. I don't know what to do...she has no family, and few friends since she hasn't lived here very long. I can't stand the thought of her having to spend the holiday season all alone, but i dont think i want back in. To complicate things more, I've always had this huge crush on my friends sister, and know that she likes me as well because we had discussed it before, the first time me and my ex broke up. b I ended up cutting it short though because me and my ex decided to give it another shot. I recently spent some time hanging out at my friends place and she was there. there was alot of flirting back and forth between us, and it seems like a great opportunity to move on and start fresh. An opportunity she likely wont be open to again if I get back together with my ex.

As you you can see im extremely confused...What should I do??? frown