Grain is hard for a horse with ulcers to digest and can actually aggravate the sores. So, if she is ulcer free it wouldn't matter, but how do we ever know that? Scoping doesn't guarantee a diagnosis. It's an indicator, but that's all. If it was my horse and I knew there was a history of ulcers, I would change the diet to assume there are ulcers present. I would not medicate unless indicated though. I figure this way you're playing it safe. Horses don't need grain, but if she is not a really easy keeper, you'll have to find something to replace it. Beet pulp of course is one way, but if you work her much you might need another grain-free supplement. Alfafa, as previously mentioned, is supposed to be good. Ask at your feed store about pelleted feed but get the ingredient list. I had to put quite an effort forth to get the list -- actually had to call the manufacturer. The locals wouldn't tell me. Go figure.
Thanks for the info : )