A trusted AA friend of mine, who knows our family well said "well she does come from a family of chronic relapsers" - I wouldn't subscribe to that theory at all. Every human being is his/her own person. She is a strong girl, and she is her own person. And anyway, she's as much you as him...and look at the model of recovery you are! We each have our own lives and choices to make. She deserves hers without the pressure of a self-fulling prophecy to live down...so I don't agree at all with your friend.
I pray that she will find her way back to the road of recovery very soon. <<Hugs>> and Christmas Blessings!!