Maybe due to poor oral hygiene doctor advised her scaling. It will help in healing

Ulcers due to sharp.edges of calculus will go with scaling but normal ulcers will not go with scaling.you can use a multivitamin tablet for 10 days or use lexanox gel if she is not allergic

Please share clinical photograph of the area in question for better consultation? Thanks!

Scaling is cleaning food debris and claculus(stones) stains around tooth via  scaling machine. Scaling is recommended once in 6months for proper oral hygiene. It otself don't treat ulcers but due trauma in ceeck or gums don't heal to fungal and bacterial agents and calculus and food deposits  in gums pockets are great conditions for these bacterias and fungus to thrive. So it's necessary to clean the muth first then wait and watch of not resolves within 7 to 10 days then dentist will refer you to an oral pathologist.