Yeah, I totally get that! And I do think it is fine describing those relationships, since yeah, ASOIAF characters are very much tied up in other people. I think the best way to go about this would be to just focus on the relationships and not so much what the other character is DOING. Like I think it being a family trend thing is alright to say too.

If you are flexible about changing things that helps a lot too. Another tactic is you can just refer to people without actually specifying names, unless it's really necessary. I find that helps sometimes.

But yeah some of this will be inevitable, I just thought I'd mention it as something to be on the cautious side with.