At least you know how she thinks. She basically wants to go off and see if she can do better, if not, then she can come back to you. If she comes back, tell her "no thank you". Let her live with her mistake.

 

I wouldn't worry about it. I'm just surprised she waited until now to break up over an excuse she could've pulled out at any time. If her parents had a problem with it, she would've pulled out of the engagement a long time ago, or maybe she shouldn't care. If her parents like you I don't see why she would bring up the excuse of being from different classes. What are you, Hindu?