try to determine if you want to marry this girl...if you do, do it...seems the logical next step if that's the reason she's unhappy and you were originally wanting marriage...despite what the stereotype is a dude can change his mind

Surprisingly, I had this same difference of opinion with my girlfriend about 3 years ago. She told me that she didn't believe in marriage and that she was not ever going to get married...I felt the opposite and we even talked about breaking things off (there would be no point in continuing a serious relationship if one of us were not willing to take it to the next level should the time come). We decided that even if we disagreed on marriage, we still enjoyed each others company and would continue to date for the time being to see where things went and how we felt.

Three years later, we are happily engaged and getting married in a week.

I never tried to force the opinion on her, instead I tried to show her that there are benefits of true love and I think that we both found someone we could trust and care for and lean on at any time. I think that is what truly changed her outlook.

So don't sweat it, enjoy the time you spend with her and show her that you love her and if she comes around to the idea you two may have a lasting, loving relationship for life. If not, you've had a wonderful time together and you have both learned a lot, but it may be better to part ways at that time.

Hope this helped!