Hi Cindy, welcome to pets.ca!
What does Riley eat currently? Have the vets given you any treatment options for the EGC?
Many times, simply switching to a grain-free wet diet, possibly with a novel protein source like venison or lamb, can help tremendously. Treatment with antibiotics may also be needed to deal with any secondary bacterial infection. Where abouts are the lesions located? If they're on her face/mouth area, it's also important to make sure her food dishes are cleaned frequently and that you use glass, stainless steel or ceramic, not plastic (which can harbour bacteria).
"To close your eyes will not ease another's pain." ~ Chinese Proverb
“We must not refuse to see with our eyes what they must endure with their bodies.” ~ Gretchen Wyler