I would keep looking. First, this pony is 3 and just backed, and won't be ready to show until next year.
Second, the photo of her moving shows her with not a lot of reach forward from the shoulder and too upright of a head and neck carriage for a hunter, usually those qualities do not improve under the weight of a rider.
Her confo photo flatters her head and neck, but shows a long back and a weak, underdeveloped hind end. She may outgrow that, but I think the pronounced sickle hocks are here to stay.