Why is she doing this to me?

ok so there this girl who i have feelings for, she said recently that she has feelings for me. ok but now on msn every time we talk she mostly says things that would make me feel sorry for her such as "lifes becoming hard for me" and all that ****, when we actully meet, she is nothing like that, she is happy as larry. friends at her school say she is fine as well but when she talks to me she sais she aint right. why is she doing this?