It sounds like a mucocele. Remar is right. They are a build up of saliva in a gland that forms a small cyst. Many rupture spontaneously.
If it comes back, your Mom should probably see a dentist, otherwise it should be fine.
Best to you,
I'm wondering if she may have had a build up of saliva in the gland. It's probably best for her to see her dentist to find out if there is still a problem.
thank you for your reply. It makes sense. I'll tell her your advise. thanks
Thank you for replying to her problem. I appreciate your answer. I'll tell her to keep an eye on it and see the dentist if she has any more problems. thanks