Is this girl using me?

[JD35]

Ok so here's the situation. There's this girl I use to work with, we're both mid-20s. She left the job a year ago. This past July, we reconnected on Facebook, and have since become good friends. Anytime she would do something with her friend group, she would ALWAYS invite me. She always invited me over to her house to hang out, go shopping with her, grab something to eat etc. She has a boyfriend, who's had no issues with the two of us hanging out, even if its sometimes without him. she would text me when she needs a liftup, and I would do the same. To be honest she's the best friend I've had in a long time.

Well about 3 weeks ago, she asked me to do her a favor. She got married at 18 to her HS sweetheart. It didn't work out and they've been separated for a few years now. So she decided she wanted to go ahead and give him divorce papers. She found out that he works at a store 5 minutes from my house. She said she wanted to go in there to give him the papers without him knowing shes coming in. So she asked me to go in there 3-4 times a week and just walk around and just get a feel for his schedule so she knows a good day to go there. I refused of course because thats just friggin insane. We had a bad fight and both said some mean things. But we started talking again a few days later.

But since I refused to do that for her, things just haven't been the same. We still text all the time, but I'm always the one to initiate the convo, she never sends the first text like she use to. And I haven't had any invites come my way since then. In fact the only time I've seen her since then was when I stopped into her work to hang out(she works at a game center). Oh yeah she did invite me to do something with her friends a week ago, but I declined because she wanted me to drive seperately and meet them there(in the past I always rode along).

So my question is, did she know all along that she was gonna ask me to do that for her, and her being my good friend these past few months was just her way of buttering me up? I've heard that girls who use guy friends tend to like turning them on. But shes never done anything along the lines of sexual teasing. Its just these past 3 weeks since that incident we've gone from close friends to close acquaintances. And the past week its gotten worse, she seems like she has no desire to talk to me.