Lovely.
Somehow I feel he sounds a bit too upbeat (well, if I were playing with any of my children I would be happy too).
I loved how they sounded when she was doing chorus, their voices matched perfectly.
As a bass player I find very weird that tendency (many guitar players have) to use the thumb to play while using the fingers to lock the hand (instead of the oppossite, it can be on purpose, to make it sound even softer).