Listen , I can understand because of corona virus, its difficult to go to your dentist. But if possible with precautions you can go to dentist. Because heavy bleeding from mouth means Pyorrhoea is in advanced stage in which bone which surrounds our teeth causes destruction because of which bad breath is there. Many times Pyorrhoea is associated with other medical conditions like
diabetes, Bronchial asthama and sometimes it because of genetics or hereditary. Many times it us because if improper brushing of teeth and improper oral hygine methods.
You just do one thing , tell your mother to Use Rexidine plus mouthwash two times in a day ..10 ml of mouthwash. Tell her to use oral gel like mucopain or Rexidine m forte gel. U can order online also. Tell her gargle after having each food. And tell her to use ultrsoft toothbrush and sensodyne rapid relief toothpaste to brush her teeth. Tell her to brush her teeth twice in a day. Tell her to use Warm water saline gargles 4 to 5 times in a day.