Great feedback everyone, thank you!
@contdes we did something as you suggest and talked about different things she is passionate about and in the end she did come back to her brother after all. She is thinking more in terms of the problem solving prompt but I’m not sure her actual problem is well defined.
So much of the Common App seems to be a guessing game. Even in terms of activities, knowing which one to place the most importance on, etc. I long for the days when we filled out our applications by hand, stuck a stamp on them and we were done!