Mostly this horse looks immature to me; I having a hard time believing she's 5.
She also hasn't had good groceries or any exercise, as she lacks any kind of muscle development.
She has a decent shoulder and front leg. Neck is short, set high and underdeveloped. Back is long, and the point of croup is set very far back, making for a short, weak hind end with a very steep croup. A little straight from the hip to hock, very, very cow hocked.
Her overall impression is of lacking substance. How much of that could corrected with good food and work is hard to say.
In any case, I am not sure I'd invest the time and training in teaching this sweet, kind girl to jump courses, she might do best as a trail or pleasure horse with some gymkhana thrown in for fun. Depends on your budget and your free time. At the level she'd likely be competing, I don't think the watch eye would be an issue.
You also didn't mention if you were purchasing her, or if she was a rescue or a free to good home. With the abundance of nice horses out there free to good homes, I think you could continue to look for a hunter/jumper prospect.
Funny, I was looking at her thinking she had a nice neck, that was long enough to balance out her rather long back.
And, I dont' see cow hocked. There is no view from the back to show if she is cowhocked or not. Do you mean sickle hocked?
Agree with the assessment of the hip and the angles. She is a bit weak in the loin/coupling area . something sometimes called "wasp waisted".
But I do not see over at the knee, in fact her front legs look good to me. She has long legs , for sure. I kind of like her and with mucleing and groceries, I think she'd look awesome in English tack.
AS for speed for gymkhana, well, I wonder about that. But jumping? she might do well at that.