If you really love her, leave her.

OP, what the fuck don't listen to such advice, please. Do not leave her if you love her. Please. Love is not so flimsy, dear Rama. People here have no fucking clue who you are or what you relationship with her is have not right to tell you to 'leave her'. Reddit's best relationship advice is LEAVE HIM/HER, no matter what subreddit.

The fact that she wants to be in a relationship with you means that she loves you, enough to see through the veils of religion. Help her, try to make her talk with her parents. She can still follow her religion in spite of marrying you. Things don't have to end just because she is a Muslim. Both of you are people of the book, and outdated dogmatic beliefs have no place in today's religion. Islam, the way she follows it, as a personal religion, is very valid. I suggest you to read works of Rumi, if you want to know more about such an interpretation of Islam. It is very personal, kind of esoteric, though.

The entire purpose of religious sanctions on frivolous love is to help people find true love. For the love of everything that's dear to you, please, don't take advice from armchair scholars who will suggest you to 'leave her' without knowing your life's situation. Love is not a joke, it's difficult to find true love. Only fools will believe that true lovers can only exist within one's own religion or sect. You live in bloody 2015. You need to take the initiative and break the ice. Your love deserves utmost priority here, because every religion in the world has always tried its best to keep love pure. It would be ironical if you lose the person you love the most, in the name of 'religion'.

Really, think about it.....you know yourself best, you know her best. You need to work things out with her family, you need to convince them that her happiness is more important than anything else in the world, and that she is free to be Muslim with you.