i'm no show-jumper but i'm an avid conformation watcher..
difficult to say for certain as her trotting shots are stills but she seems a liitle short on the near-side track-up than the off, sugesting a possible back problem...sacro area??
if i was to be buying her i'd like her to be a little more behind, and to get her hocks under her when jumping....again back problem??
i'm sure she would be vetted beforehand, which hopefully would show any problems.
I have an han mare and she is lovely natures and fantastic allrounder but excells in SJ. They can be difficult to keep weight and condition on but thats minor as her temp and ability.