Q: Daughter locked out of 5C

My daughter did an update at home to her 5C before leaving on our trip.  Said complete and successfu.  She goes to login, enters 4 digit passcode fin, then stuck at iCloud. Asks us for email and passwor. We know the email but no idea of password. We are directed to contact previous owner but there is no previous owner. We are not the the most tech savvy and may sound naive on how/what iCloud is and how it work.  Thanks