you dont want to lose your chance with this person; the holiday romance of theirs might be long over!
The fact that other people noticed you and her were close, then its likely she likes you a lot as well. Have you got her mobile number? if so why dont u text her and just ask how she is?
However if it seems she's not that bothered and may still be into this holiday romance of hers, Id wait until uni and just see what happens then!
Whatever you do, make sure you take any chance you can to get a bit closer to her otherwise you might reget it!