The girl i like/have a crush on still has feelings for her ex! What should i do now?

[tiffonn]

Well i have met her 2 times before(both times we were together for 2 hours talking while on the bus) and once we talked on the phone for 3 hours. Well in this time i have found out that she is kinda different like the girls i have met and i have this inside feeling of those butterflies when i think about her and stuff.
Also i have the feeling that if i dont make a move i might lose her as a possible future lover and be only a friend.
The thing is that she is retweeting these texts in twitter that about past relationships, like ''the times we had and when i kissed you made me happy, but it doesnt mean im happy now'' or something like
that. This makes me think that maybe she is not able to forget her ex or stop thinking about him.
So ive heard that no matter what happens, a girl will always have feelings for her previous boyfriends.
So should i make a move at some point when i feel is right or i shouldnt?

P.S: im 19 and she is 16.

[Matt]

Date someone your own age and move on from her.