She looks very TB... high withers, deep girth that ties into smaller hindquarters and long legs, long neck, long face with refined features, She also has the thick legs and big hooves of a mustang. I do not see the stocky build of a quarter/mustang. Her conformation says to me she would be extremely quick on her feet.
She is built very down hill but the level between the knees and hocks is very good. Her pelvis is rather small compared to the lenght of her back and only makes up maybe 1/5th of her over all body lenght so its a rather small engine. She has a very steep shoulder which will probably inhibit her from extending her gaits out and make the ride a tad rougher.
♪♥♫ A horse which stops dead just before a jump and thus propels its rider into a graceful arc provides a splendid excuse for general merriment.
~Duke of Endinburgh ♪♥♫