Does my friend not want to hang out with me or something?

If it matters, I'm a guy, and she's a girl. We've been friends since kindergarten. We used to be the bestest of friends. High school came -- I got really shy and she became really outgoing. We didn't hang out AT ALL freshman to sopre year. We talked A LOT over text, though. I helped her a lot with her problems, basically. We were and are CLOSE. The one time we did hang out was over the summer of sopre year -- that was because she felt bad that I was sitting home all day, friendless, doing nothing. She does care about me, a lot, and she's a great friend. She wants me to become less shy, and make more friends. Recently, now that we're in our junior year, we began hanging out a LOT more. The weird thing that I've noticed, though, is that we never hang out just her and I. Not that it matters -- it's just a little weird, I guess, as she hangs out with others out at the mall, around town... we go places with her mom, we play video games... yet, once I suggest we go and do something -- like go to fireworks or something, it's as if she makes up some excuse. She says she's really busy, or has to clean, or has a lot of work, or isn't thinking that far ahead... I feel like the only reason she's hanging out with me is because she feels sorry for me, I guess, because of how shy I am. And she'd never want to hang out with me -- like just her and me, because she'd feel like I'm boring or embarring to be around or something. I don't get it. What am I doing wrong? Am I just crazy or something? Or does she actually not want to hang out with me?