Don't over think this. Just have fun with her and don't take the relationship seriously if it seems like that kind of thing. You'll both change as you grow up so it's rare that you would stay together. Keep your options open. Date others while you date her.
You might see this again in the future with other girls. For example, your girl wants to study abroad in Spain for six months while you stay in the US. Gee, I wonder why she would want to do that? You can either be cool with it and date others until she comes back or if it's a big deal tell her you don't want to see her.