Should I think she's really interested in me?
How do I find out if she really loves me?
There have already been rumours about her being engaged with a guy in school. She even discussed with my sister that she had had 97 guys who had proposed to her.
Now, is she faking before me?

If she is engaged to someone else, I don't know why you would think she loves you or is interested in you. If she is texting you and is dating someone else, it say to me that she has no problem dating a guy and talking to another.
I would not take her seriously.