The tack and rider, combined with the position of her head, make it hard to see much of what needs to be seen. I would definitely take your camera with you when you go to see the horse and take some good shots then to bring back and post for a better evaluation.
I think her biggest problem is that she isn't standing in my yard at the moment. Very nice looking buckskin & nicely dappled. When you go to see her, I hope you can get the confo pictures & those that are good at that can say what they think.
You can still tell a lot from a horse with tack on, especially when they look this good. I think her back isn't long but the saddle is 1-2 inches set too far forward. Its on top of her withers, not where it should be sitting. I like everything about her I can see. Alert expression, great neck tie in, nice front legs, awesome hocks, decent bone, strong hip...glad you're going to see her. Let us know how she is in person!!!