Dear Lybrateuser, - She should maintain oral hygiene by brushing teeth after every meal, do Listerine solution gargles twice a day
- get a checkup done by a dentist
to rule if any tooth is causing the problem, also a biopsy of the ulcer
may have to be taken for exact diagnosis since it is a long standing problem
- avoid spicy & hot food, drink plenty of oral fluids
- blood sugar
should be regularly monitored & lowered by proper diet
, exercise & medication.