Think carefully. If both of you are not willing to give up something for marriage, is the foundation of your relationship strong enough to desire a life long marriage committment?
As a Catholic, you should have a Catholic marriage (which allows for a mixed marriage, with dispensation). Have a good start, because it is a choice of life long commitment.
Find out about potential problems that can arise from such mixed marriage. What about her family, how open they are to the idea of mixed marriage?
Once married, there would be no turning back, think about it. Both of you should reach into some understanding now in agreeing to things of common interest, which must be sorted out as both of you enter the marriage covenant.
God luck.