^^ neither does my horse Monty and yet he's jumped 4' (he is only 15.1hh and likes to take the long spot) - plus the OP says they want the mare for lower level stuff. I don't think conformation is SUCH a huge issue when you're talking about low levels. Sure, it leaves you things you'll need to be more aware of (I need to keep an eye on Monty for arthritis and tendon strain because of his shoulders and pasterns) but pretty much any horse can manage low level dressage and jumping.
With this mare's faults you will need to be aware of arthritis and other concussive issues due to the poor shock absorption of an upright shoulder/pasterns. Her hocks are weak and may be prone to injury but if properly conditioned she will be fine for lower level jumping and dressage. She looks a little over at the knee which may actually be a good thing (decreases strain on tendons, BUT may increase wear on the bones, leading to early arthritis).
Conformation CAN and DOES dictate the maximum of what the horse is physically capable of. Heart matters far more, and if the horse loves what it does it will push itself to be the absolute best it can, given the opportunity. If it lacks confidence, or simply isn't brave enough or passionate enough, all the perfect conformation in the world will not make it good at its job.
I was blessed to have a VERY well conformed pony that LOVED jumping, but that was just too small to really excel (he was 12.1hh and very scopey for his height but would not have taken me where I wanted to go). All the same I was devastated when I outgrew his saddle, which was on the big side for him, and we had to sell him. I now have a "nice trail horse" that excels at jumping and eventing DESPITE his conformation, and all because he enjoys it so much. Yeah, I need to expect that he may become arthritic very quickly, very soon, and I need to be aware of that. I also need to be aware that because of his upright shoulders, he won't be capable of as much lengthening of stride as a horse with good slope. But that doesn't change how much he loves eventing and how good he is at it! I'd rather have a happy horse and retire him early, than a bored witless horse that's good for another 10 years.
I do agree that this mare will never be a world cup showjumper and is highly unlikely to be capable of courses bigger than 3' but there's nothing that should stop her competing successfully at a lower level.