Yes, I am afraid so. Believe me, when an addict is in the throws of active addiction, one of the last things they are concerned with is being abandoned, they could care less...they are all consumed with their next hit and how they are going to secure it.
Because I let my exabf go didn't mean that I didn't love him, that I didn't care...it mean't just the opposite...I loved him enough to do the right thing for him, let him go to find his bottom, to learn how to be a responsible adult. Unfortunately, it may be too late for him, he's been drinking and doing drugs for over 30 years, the longer it goes the harder it is to break the cycle.
I don't know the age of your gf, but, the sooner she hits her bottom the better her chances are for recovery.