KK,
I can appreciate your situation, it's similar to mine except that I am the alcoholic (sober 15 months today coincidentally) in the relationship. My gf quit drinking when I went to rehab - the gratitude I have for her and how my life has changed with her by my side defies words. There are two sides to the relationship and there are two ways your relationship could proceed.
1. You are willing to live with her as she currently is.
2. She is willing to go to whatever length she must to stay sober.
You need to first figure out what your feelings are for her and under what terms you are willing to stck this out. Then tell her, and if you are not willing to do (1) then she's got a decision to make (2).
Best of luck, KK.