What is it you are so 'confused' about? That she is using and not in recovery? There isn't anything to figure out.
I guess what pains me the most is that you are putting so much energy into someone that gives ZERO in return and her not giving back has nothing to do with the drugs.
Many addicts are aware of the pain they are causing. She may be or may not but she doesn't care that you are suffering Steve. You are hearing what you want to hear.
That is the part that is maybe painful for you to acknowledge. All you are doing for her will not even remotely guarantee a spot in her life now or in the future. You kind of already know that.
And to know that you are putting so much energy into someone that doesn't see you as that important is the piece that you may be having the hardest time accepting. It is also the hardest part for many of us witnessing this.