Just thought I'd weigh in.
(Marg, thanks for re-posting the link to the Ballastexistenz website where I first found out about the ring splints, and the site itself)
Although muscle strengthening exercises don't help the tendons , ligaments or joints, the exercises do provide a means of compensating for the laxity in the ligaments by employing muscle strength.
I am hypermobile, and had the gamut of physiotherapeutic assessments as a child. One of the recommendations was that I do lots of muscle strength work. I have found that, over the years, this has allowed me to hold my body together using muscle tone where the ligaments would normally do the work.
I am still terribly prone to what I think of as "rubber-band-itis", for example, I walk over on my ankles all the time and do some spectacular tripping and falling as a result. However, for most people a turned ankle means a strain, sprain or break. I just stretch and then bounce back, hence all the falling.
If Duckie is turning ankles and things a lot, then this might be her issue as well. Tensor bandages (I think Ace is the U.S. equivalent) and braces helped me a lot as I was growing. This has gotten better as an adult, since I finished my growth.
Sorry for the rambling post...I''ve been travelling for work and just want to get these thoughts out before I fall asleep. Please let me know if you need more info. I have lots of it, just not to hand in this-here hotel room.
Trinity