So I've unexpectedly had a class with a girl whom I was friends with and haven't seen for a couple years. I didn't think much to it, but 4 days later ( today ) she texts me telling me that I changed a lot ( I started shaving my head, getting more facial hair, better clothes, started working out ). Anyway we texted for a bit and she asked me to start sitting with her in class, and being super nice and all. I took the way she texted as a sign of interest so I told her straight up that I'm going to change class ( I am), and I'm busy rn (also am ) but in about a month I'll be sure to hit her up.

So 2 questions here. Am I wrong to take what she said a sign of interest ? And do girls really have low attention spans ? I mean sometimes I just can't go out with a girl or can't approach due to reasons, will that fuck up my chances with her, by making her get bored ? I've never really been so busy in my entire life and not used to rescheduling with girls so I would love some insight.