Back to the OP, your DS may take consolation in the reporting on this study, which showed that individuals who self-identified as belonging to a particular House and then took a more rigorous, science-based personality test scored highly for the traits related to that House, regardless of which House the Pottermore sorting test placed them in: http://www.theatlantic.com/health/archive/2015/06/harry-potter-house-personality-study/396491/

Maybe don't mention that the one group that wasn't consistent was self-selected Gryffindors... though personally, I think substituting "extraversion" for "courage" is a mistake there.

A relevant bit from the article for Nyaanyaa:

Originally Posted by article
Hufflepuff’s defining trait is “nice.” Its mascot is a badger. Its members, if Hogwarts were an American high-school cafeteria, would be the ones in the corner, frantically combing the trash for their retainers.

:-P~~~