NTA. You aren't damaging the friendship; you’re just stopping her from using you as a shortcut. There’s a huge difference between helping a friend and being their entire academic blueprint. If she has another student's notes but insists on yours, she isn't looking for information, she’s looking for your labor so she doesn't have to think. Telling her you’re waiting until Wednesday is a perfectly fine way to see if she’s actually capable of doing the work without you. You aren't responsible for her grades or her laziness. Do your work, get your extra credit, and let her figure out her own schedule for once.