Besides, a sister's graduation is surely a much more inspiring event than the NUMATS ceremony! Does he get to go to it, or just to hear about it? You don't say what his sister studied, but maybe, if he'll be there, she could show him briefly round a department that does something he's interested in (maths?) or ask another student to do so if there's little overlap between their interests?
I hadn't really thought of that, but you're right. I'd much rather him aspire to graduate from college than to get another NUMATS award! 
She is getting her degree in science, which does interest him. And it's first-come, first-seated, as far as tickets, so he will get to go. He's close to his siblings, so I think he'll enjoy it. 
