I just learned this the other day from our vet: if a grain is not consistent in the seven most important amino acids, as in if it is deficient in one, it will throw the whole balance off and do very little for your horse, so make sure you’re reading the ingrediants! :)
I would add feeding hay a third time. You ca also add oil to her feed to increase the calories without feeding loads of feed
buckeye feed has done wonders for all of the 43 horses on our farm! the youngest is 5 and the oldest is 26! it has also helped all of our OTTBs that were hard to keep weight on. They all get Buckeye Safe n Easy and then some that need it get a half cup of Grow n Win along with their Safe n Easy.