Should I just let it ride with this girl or what?

So I have a friend, hes actually a real good friend, and I've known him for about 4 years. about 3 months ago I just recently met his sister, didn't think nothing of it at first, I'm actually a very respectable man, and am not an to ladies, so suddenly she starts coming out, hanging out with her brother, and i happen to be there most of the times, she turns out to be a real cool girl, my buddy invites me to there 4th of July party, i get there and its a family party at first, my buddy just stands there and doesn't introduce me to anybody, she pulls me and introduces me to her parents and family, not sure what to make of that. Then she invites me to a picnic, just me and her, turns out its a biker picnic lol, but she knew them because she use to take care of these guys at a bar, nothing like hells angels or anything, so I start buying drinks and little stuff for her but I know shes not after my money because she always returns the favors, she also pays for a lot of things so it evens out, now for the past three weeks I've been spending a lot of time with her, I've gotten to know her and shes gotten to know me. last week we went out, and we all know the same people, that night I was mad at her because she was getting way to much attention from friends, which kind of made me jealous but were not officially going out, but she totally knew something was wrong that night, the next day she sent me a text message saying that she was sorry and to tell her what she did wrong so she would never do it again, now it wasn't just guys talking to her, guys where touching her also. Well i picked her up the next day and we talked, and I let her know how i felt, that I did get jealous, and she told me straight up she just wanted to be single at the moment, and i can totally respect her choice. She has 3 jobs but on her free time she usually hits me up which also kind of confuses me. But Ive been recently going thru this phase in my life where I know I need to clean up my act, so i changed my number, I use to smoke a lot of weed, and all my friends did too, but i mean don't get me wrong, I don't regret anything and i feel bad for just disappearing like that but I need to move on with my life. but before I did that I left on good terms with that girl, but didn't tell her I was going to change my number, and haven't talked to her or anyone for the past week. Now the question is, before i started changing i bought her and myself a ticket to lollapaloza, would it be weird if i hit her up next week to see if she still wants to go? I mean i have an awesome time with her but i think it might seem a little weird? So i mean am i on the grounds to be confused? and does anybody know what to make of all this. Any suggestion or answer would be good thanks.