Chris you should have them check into what will be available this spring. As far as a youth class that young you would have to check to see what is planned for the year at Sail Sand Point.
There usually is a Wave class and Wave Cruising Camp for the kids that goes on.
But your nephew's family should check with the local Hobie group there, and with SSP because we have a youth serries planned that will emphasize the Wave and new young sailors.
In April we have the first event planned for a resevoir in Eastern Washington that will be a family camping/sail trip. There will be several Waves there for kids to just have fun with.
Being the first event of that serries we will be focusing on familiarity and fun on the Waves.
There will be a clinic for the kids to follow in May and then a Youth Only Regattas at SSP in July and September.
In this serries we hope to introduce kids to multi hull sailing and build from there. My 9 year old daughter will be jumping into this with a couple of her friends.
So invite them out and give them our contact info, we'll get them started.
http://www.sailsandpoint.org/
http://www.div4.hobieclass.com/
And Chris you have my contact info pass it along if you like.
Mike Hensel