KCB said:
I am a member of an adoption support group, and I can say unequivocally that we are be-devilled by our histories in some way or another, regardless of our place in the triangle.
I'd be uneasy casting the Devil as "adoption" as it puts a really negative spin on something that is not, in and of itself, negative. Unless there immediately pops to mind the memory or knowledge of an adopted "ancestor" who was really miserable, I don't think this ought to be the first thought about this card.
And keep in mind, even though the title of this thread is "devil as relative" it's really "Queen of Wands" as relative. The relationship to the querent is where the Devil card came up on the spread. I think if we're going to see the relationship as adoptive, we need a better explanation than the one you offered for why the Devil should stand for an adopted relative.
I also think there is another way in which the aunt fits perfectly: she is a relative with mental disorders and an addiction (elements common to the devil card)--which could be genetic. In other words, her nieces and nephews may share a propensity for such things even they haven't appeared so strongly in them.
I happen to have a problem that I share with a childless uncle. He has this genetic disorder and so do I. Hence, I would say that I'm related to him not only by way of my mother, but also by way of this shared genetic disorder. If that gene was for say, alcoholism, then I'd say that the Devil would work out just right in indicating how I'm related to him.