Having had an alcoholic step-father during most of my teen years, I'm not very tolerant of drunks. I know how hard it is for alcoholics (and your friend qualifies as one) to break the addiction. Therefore, I'd just look elsewhere for playmates.
On the other hand, we owe it to our friends who have problems, no matter what the issue, to try to help. So let me just say, "Talk to her about your feelings before she starts drinking." You run the risk of her becoming angry, a common reaction with boozers, but such a reaction would likely convince you that there is nothing you can do to help until she decides she must help herself.
If she understands that there is little you can do beyond offering her concern and understanding, you may be well on your way to a very satisfying friendship as well as a very attractive playmate.
Good Luck!
Mr. Alura