For 1, if she aint a racer anymore, she doesnt need that much grain. Her required energy levels are low - feed fibre not starch. 14 lbs of grain is about 6 kg. thats a lot. 500 kg horse needs about 10 kg dry matter feed per day - 6 kg in grains and mixes is too much..
also, grains are very high in starch and their stomachs cannot handle big portions, 3 lbs of oats already has enough starch for one meal.
with good quality hay, sugarbeet pulp, soybean meal, or even sunflower meal, some alfalfa etc she would get lots of good quality fibre that will help with weight gain. ok, for weight gain the food should be about 2.3-2.5 % of the body weight, but not all grain..
sorry for the rant, but 14 lbs of grain made my eyes pop.
Otherwise, WELL DONE. She looks very unhappy in the first picture, and very "dry" as in plain muscle around the bones. the muscles needed for running.
overall she looks much better, just need to work a lot more with her neck. keep working with dressage and should be fine :) Takes time to build good muscle on the horse when they are used to working in a different way.