You have to consider what you are doing and how those you both care for could be involved. Maybe she is big on family and would like them to be there to see it. Or enjoys large groups and wants it to be public, at a family event or other public event. Or they could be involved in the proposal itself by helping get her to location. Consider who will be there for the big question but, also who will know about it before hand. Although it’s not always practiced, a lot of people still really appreciate asking her father for her hand in marriage or the blessing of both parents.