My concern about the snowcap is her build. I have a 14 hand QH that I'd have no problem putting my 6 ft tall husband on; she's stocky and solid with good sized feet. I know cutting horses are usually on the smallish side; as are polo ponies. It's just that this filly is pretty narrow, and there isn't much depth to her body; I'd be surprised if she weighs more than 600 - 650 lbs.
As I said, she's just shy of 3 years old. Her 15-year-old owner has been riding her for about 6 months; the shadow of the first payment had hardly crossed the breeder's palm before the girl was on the horse's back. Recently she told me that she's been jumping her over sections of telephone pole that are lying in the pasture. The adult I've mentioned is the 15-year-old's grandmother; for all of her enthusiasm, she hardly knows one end of a horse from the other but is eager to start taking the filly on trail rides.
I'd heard the 20% rule before; my understanding has been that it applies to mature, fit animals. I know another adult that was being pressured by the breeder to start riding this filly when she had just turned 2 (you can sell 'em for more if you can say they have been ridden, don't ya know), but this other adult, though barely over 100 lbs herself, declined because she was afraid of doing damage to the filly's growing bones.
The grandmother keeps coming to me for advice; my advice was to buy a good, solid, been-there-done-that for a family horse. Instead, she bought this filly, and her granddaughter (who knows everything there is to know about horses - after all, she had, like, 6 lessons when she was 9) has been training her. I feel like I'm watching a train wreck in slow motion. Am I, or am I just being alarmist?