Old email

My daughter deleted her old email address because she needed a more professional one for applying to post secondary schools. She needs access again because Facebook has somehow lost her password or changed it and will not allow her to get a new one because her old email is no longer valid. As the old one is deleted she cannot see her old emails and cannot give detailed enough answers to Microsoft to have them reopen the old account. How can she regain access? Both old and new email are hotmail.