Life is about choices you make buddy. Sometimes choosing becomes utterly tough, especially when it comes to choosing your life partner which demands what-to-do-what-not-to-do sorts of sacrifices you have to make. Carefulness, maturity and far-sightedness play a big role in your kind of case. I think often times we discount our parents opinions when we should at least hear them out because we think we have gained enough maturity at least to decide our own future. But listen to them, they would never want you to suffer, provided, have your say as well. May be they are not able to see the girl via your eyes, may be they are missing out something that needs to be understood. Importantly, talk to the girl as well, they question she is asking looks kiddish, but is highly important as well. She needs to understand that today if you choose her over your family, tomorrow she might be the victim of abandonment as well. Its a plain human nature, nothing personal.

Bottomline, dont compromise your family. Work out between you and your girl.