The Jet city doesn't seem bad for 20W
not sure if a 10 year old would really take care of a tube amp though 🙄
I almost bought an Orange Crush. those are good sounding, good for bedroom levels. plus the amp is powerful enough to drive bigger speakers. so down the track it can be mod'd to use an EX.SP. with it.
or get the EHX 22caliber and a cab. it'd be fun to get some of the tech21 amp modeling pedals to play with that kinda setup.