No, you dont have to wait 24 hours after capturing her. I caught all of them within 40 minuets. If you changed the time on your clock BAD IDEA! It takes about 24-48 hours before you can catch or do any time-based events after changing the time.
You could also be looking for her at the wrong time, I believe she appears at 40-00 minuets of the hour (I.e. 11:40 - 12:00)