This is Mouse!
So last night I noticed she was trying the wheel out again but was struggling to move it. I adjusted it a bit and it was spinning more freely but definitely not spinning as well as when I originally bought it, so I'll be looking into getting a new wheel for her. I don't know if I could return it because I've misplaced the receipt, but I'll probably sell it online or something.
Thank you all so much for the advice! I can't wait to get more comfortable with her!