My rescue girl was in far worse shape than that 7 months ago. Main thing is free choice hay(good quality), and gradually work her up to turnout as much as possible. As far as grain, there are several good ones out there. Equine Senior, Legends, Strategy, or Ultium are great, and mixed with a sweet feed(Omolene 200) and rice bran it's a great mix. My girl has gained about 400 pounds in 7 months, but still has about 100-150 to go. She gets 3qts of Legends, 2qts of rice bran, and 1qt of Strategy both am and pm. She will eventually be on 3qts Strategy/3qts rice bran, but we are weaning her over as we just switched barns. Don't do it too fast, or you end up with even more serious problems. A good worming never hurts either. Thank you for rescuing her. She looks like a sweet soul, and is very pretty. Can't wait to see pictures of her progress!