Thought I would explain a few things a little more. Her previous owner had two pens, one for each horse and one feeding stall that was accessible to both horses. Unfortunately the one horse would boss the other horse around and not let it touch the feed.
I stand by my comment regarding the previous owner. If he/she KNEW that this was occurring, they needed to take the time and make the effort to arrange something different rather than continue to allow it to happen.