I don't have a horse healer. I could make one out of Clarine, but it would be quite resource intensive because I'd want to do it properly.If you have a horse healer, unequip her attack staff and make sure she has rehabilitation. She will run around the map and heal or do nothing. Run either renewal or live to serve 3 if you have Elise to keep the healer alive. If you have Miracle, that can have her survive a hit along enough to get some HP back on player phase.