It is honestly a very simple answer TALK to her. start now if you want to keep her talk about anything that makes you question this relationship and why. if you feel out of place in this relationship or if you feel her heart is not in it, well then your not in a relationship are you? just talk to her if she loves you it will all work out...
DONT TAKE IT PERSONAL BECAUSE I DO THAT ALOT TO BUT ITS JUST BECAUSE SHE THINKS THAT EVERYONE KNOWS THAT YOUR HERS AND SHE DOESNT HAVE TO SHOW IT SO JUST CHILL OUT AND IF YOU HAVE TO! TALK TO HER.
good luck to you!!!