I think it comes down to the question: do you love this particular horse enough to adjust your riding to her abilities, even if it means holding off on jumping? Or would you rather have a horse that can take you to higher levels?
This is just me, but I would never sell a horse just to move up in my riding ability. I'm not saying it's wrong, I just wouldn't do it. When I buy a horse, I have every intention of keeping it forever, for better or for worse. I wanted to be a hunter jumper at one time, but my horse doesn't jump.
So now we just stick to trail riding. It's all about compromise.
If you do choose to sell her, I don't see anything wrong with it as long as you know she'd be well cared for. It's completely up to you.