Not sure why im in love so easily

Ok so im not quite sure what to do in this situation. Me (being 19) and a 15yr old girl have fallen completely in love and i mean like crazy in llove, almost to the point where she wants to run away and live with me but i told her not to do that. Now her parents are perfectly fine with me being 19 and dating their daughter, i have even talked to her mom about this multiple times. This girl also acts very grown up for her age mainly because she has been forced to grow up very fast because of her shitty childhood and abuse in her family. But this is what the problem is, im not sure if she is in love with me because i just seem like the knight in shining armor that has come to save her from her family problems or because she is truly in love with me. I have talked to her about this before and she swears she loves me 4 me but i just need outside opinions. I am ready to wait for this girl to turn 18 but i just need to know if our love is real. Thnx

What could you possible gain from dating a 15 year old? Do you have any idea how much the both of you will change in that time?

Sorry to be the bearer of bad tidings, but a 15 year old is incapable of providing you with what you're looking for. She's just not emotionally developed enough to experience "real love", regardless of how mature she appears to be.

Please remember that because you're so much older and because she has emotional damage from her bad childhood (believe me, you can only see the tip of the iceberg, here), you have a responsibility to her not to mess her up. Somebody has to keep this thing on the ground, and it's YOU. Don't forget that.