I'm quite new to seduction and am slowly starting to pick up some useful advice.

I recently grew a pair and started talking to a HB8 in my class. We have similar interests and she seems interested in me when we talk (asking questions about me and not just answering mine). I suggested we get together to study for our upcoming exam and she said that's a good idea and gave me her number on Tuesday. I texted her about 10 minutes after as a "here's my number" type of thing with a reference to something funny from our convo earlier. I got no reply. Then we had another great chat after class on Thursday and I suggested this weekend would be a good time to meet up and she agreed. I texted her last night asking if she was free on Sunday and she gave me the "I forgot I have family stuff planned and will be super busy" excuse.

What do I do? I haven't replied yet. It seems like a bullshit excuse to not hang out but I am a long time sufferer of oneitis so I'm wondering if I should just leave it and move on or reply with something or just not reply and see her in class on Tuesday? Any advice is welcome!