I don't know about my kids (haven't tried instruments), but I am low tone with hypermobile joints in my hands. As a 9 year old kid going into 5th grade band, I picked clarinet, and played up through college. It ended up being hard for me at the higher level because I couldn't really hold the clarinet up properly. Since my thumb was "double-jointed" (as my clarinet teacher pointed out), and I had a very awkward hold on the clarinet, it was very difficult to move the fingers on my right hand.
I'm not sure if DS will ever be coordinated enough to play an instrument, but I'm planning on steering away from instruments that are heavy or hard to hold up.
Flute was eventually hard on my hands for the same reason.
Piccolo was easier-- less mass.
