If she does have ulcers, the best hay to feed is alfalfa as it is the easiest on the stomach lining. If her temperament is too high then I suggest a mix of what you are currently using and alfalfa. As for the weight problem, my picky gelding has the same problem- he gains weight but looses it just as quickly (usually due to stress) what works for him is twice a day rice bran mixed in with his regular grain (again, easier on the stomach) and two cups of soy oil with the feed. It’s important to use soy as corn/canola have been linked to inflammation. Also, when starting oil one must only feed a small amount and slowly increase it to a larger amount or the horse will have diahreea. I hope this helped and best of luck.