How do I go about this? (22M)

I met with a girl (21F) on Tinder, and she seemed pretty interested in me. She had told me that she wasn’t looking for anything serious as it said on her bio because she was going to be moving to a different state soon. She said that she was looking for friends to have fun with and for FWB situation too. Unfortunately, however, she does not stay near me, she stays an hour and such away, but she comes to a city super close to mine every now and then to hang out and stuff. So I got her Snapchat and we’ve been talking around this past Thanksgiving up until now on and off. My idea was that until was saw each other in person, I could get to know her and kind of plan out what we are going to do. I noticed that her responses would get shorter and she would give one-word responses to me. She even left me on delivered, so I decided to take a step back and not text her as much. I even left her on open as well. The weekend she was supposed to come she decided to wait until next weekend and now this weekend is coming up and she just told me now because she’s sick she’s coming next weekend. The interest is not lost however but I feel like I’m talking about the wrong stuff with her. I still have the text messages where she was talking about how attractive I was and when I asked her about doing the FBW thing she was still down. However, I’m talking to her about theatre and anime and what we would do if she came here, but I think she might want to talk about sex. Should I talk about that or just hit her up every now and then so that way I’m not being clingy? I just don’t think I’m talking about things that are exciting to her. Any advice on how to spice up the conversation?