The photos of hypermobility available on the web are pretty severe. I second (or third) the recommendation to look into a connective issue disorder. I have EDS and my son has an appointment in two weeks with a geneticist to see if be has it. He also had tortilla ears when he was a baby! Now they look normal but remain very foldable like mine. It can actually hurt a bit if we sleep on an ear wrong. Strange huh?

So yes unusual joints in parent and child, DCD, and possible Chiari,
are all linked to EDS (and maybe other connective tissue disorders).

I would go to ednf.org and look for a recommendation on a good specialist to go in your area. There is a message board similar to this one.