Robert,
I second what everyone else has said. For mouth sores an md long time age suggested rinsing my mouth with hydrogen peroxide. If Cathy can tolerate it. Also I have found if I start getting a sore I increase my zinc tablets. Zinc heals & works wonders. It is worth a try. My husband has had problems off and on with cold sores, the zinc seems to have helped him.
You have lots of friends here. Just continue loving her.