firstly, it depends on what your definition of long distance is.
secondly it depends on how long you are apart for.
thirdly, it depends on how realistic you both are about seeing other people and what not. IF you keep the relationship locked up tightly, it's more likely for stuff to occur, but if you keep in contact and hook up every once in a while and are still open to see others when you go back home, it does stand a chance of lasting throught he void of distance and time.
if you think she's worth it, more often than not, she probably isn't.
attempt the double bluff to say to chill things, if she really likes you, she'll say she is but actually won't, if she seems fine with it and moves on, best thing is that you do as well.