TL;DR they are members of the 1%, he runs the family's charity organisation mostly by himself, and sits on the board of the family's business but it mostly runs itself. the other siblings can do whatever, though I did list their careers as 2 lawyers and one surgeon in his bio. that can always be changed. Longer version of Nolan's set history.
for Helena she would be the 3 sibling and I've always played it he is closer to her than the other siblings. there would be a sister between him and her (Dream face of Cate Blanchett) and they have a baby brother who is at least 15 years younger than Nolan. I've tried to be very vague about the siblings to give anyone who picks them up as much freedom as possible to build a character.