If she'd let you work with him, maybe you could use him to expand your disciplines. If you're the only one who ever works with him, she might be willing to sell him to you eventually.
At least he's not in a neglectful situation. Maybe next year she will decide to find a new owner for him if her plans do not pan out, or maybe she will turn things around and work with him. Either way, if he's healthy and his basic needs are met... (yeah, its not ideal for a horse that SO much...