Yeah, there are plenty of people who choose not to go on the same path of addiction as their parents did before them. It may require a different lifestyle, though. If a parent is an alcoholic and you have a typical life, maybe it's easier to not go down the path than if your life is filled with clubs, parties, special events, the entertainment business, etc.
Its a shame she didn't make it even as far as her mother did.
I do believe some people have an unconscious (or not so unconscious) death wish. If so, what a burden to carry.