A child who made As her first time through second grade may well be bored going through the same curriculum again. If you decide to let her stay in second grade, ask if it could be worked out for her to go to the teacher for gifted students or to a third-grade class for part of the day. You will probably want to have her assigned to a different teacher if she stays in second grade for another year.
Also find out if there is some other reason why your daughter doesn't want to move on with her classmates. Has someone been teasing or bullying her? Is she afraid of something? Has she heard that third grade is really hard or that the teachers are mean? If any of these are issues, they can be addressed by the staff at the school.