Good decision. I have had horses sent to me who were stunning lookers with every advantage great conformation can give. However, they lacked the desire to do the job and were found lacking.If they have no heart, there is little you can do. Luckily, this is not too common for me.
I would start by trying to build her top line. That would make a big visual difference. The new photos of her look much better with the better weight.
Good luck! Keep us updated on her progress. When she makes the cover of the Chronicle of the Horse, you can feel free to snicker at all of us!!