okay so when I was younger I remember watching this film, it was around 10 years ago so I’ll say 2005..
it was about this group of kids and they’re all friends but one girl is one of the guys sister… Anyway they go on the hint for treasure or something along those lines, and try to find this princess, at the end if the movie the brother figured out it’s his sister because of this birthmark behind her ear and because she’s lactose intolerant… That’s all I remember of the film, it was 10 years ago that I saw it! hope anyone can help and thankyou in advanced!!