This is because of improper digestion. So please give very light food which are easily digestible to her. Avoid all diary products and chocolates. Give the following Ayurveda medicines for 45 days.
Pippalyasavam + Abhyarishtam 10ml thrice daily before food.
Rajanyadi Churna 1 teaspoon with honey twice daily after food.
Ojus Syrup 1 teaspoon thrice daily after food.
Stomatab Capsule- Open the capsule and apply the powder to the canker