I went back and looked.. and remember I said she was a bit straight behind? Now look at her trotting and walking and you will see she has a shortish stride behind and sort of stabs her hind feet into the ground. This is what an over straight hind leg does.
It is not a horrid thing by any stretch.. and with training she will do better I am sure. Probably make a very nice lower level equitation over fences or lower level hunter. Some dressage training will help her move better and get her ring of muscles working.. and all that will do is make her more able to do her job.
Not a bad horse at all.