Hi,
Welcome to ehealthforum.
Emergency contraceptives work if taken within 48-72 hours of the unprotected intercourse. The bleeding that she had after taking the pill could be the withdrawal bleeding induced by the emergency contraceptive. If it was close to her expected periods, then her normal periods would be delayed as the endometrial lining that got shed during the withdrawal bleeding needs time to get rebuilt to result in normal periods. Wait and watch for her periods. Avoid intercourse in between. If you intend to remain sexual active, consider getting her started on regular birth control measures to prevent pregnancy.
Take care.