Doctor Answers (1) on Sharing food
I can understand your concern.
Let her eat how much ever she wants whenever she wants. There is no need to stuffing things in her mouth. Its a unhygenic practice and she should stay away from such people.
I cannot tell you if she can suffer from any infection or not because it depends on that guy is he is having anything.
Ask her to have food on time and drink plenty of fluids and stay away from such practices.
Best regards. Dr. Anil kumar jain. Bangalore