Up the alfalfa. Safe roughage, good energy, lower sugar than grass hay.
Watch the herd dynamics a bit, something might have changed, where she doesn't have access to the bale, is being bullied, which in turn, can affect her stomach.
I'd work her less also, until she's back or well on the way to where she should be.
Ultium might be a good idea also. If she's working hard, the amount of fat she needs goes up, too.