Is it permissible for a woman in her waiting period to sit with her mahram (relatives one may not marry), because it was said to her, “Do not uncover yourself and do not sit with a man”?

Question:
Honorable Shaykh, may Allah grant you success. This is an elderly woman, approaching eighty years of age. Her husband recently passed away, and she is in her waiting period. She asks: If her sons or her brothers’ sons come, is she allowed to sit with them and greet them by shaking hands? Because some people tell her, “No man should sit with you, and do not uncover your face to a man.”

Answer:
And there is no power except in Allah. As long as they are her mahram (relatives one may not marry), she shakes their hands, sits with them, and uncovers her face, and there is no blame on her for that. Yes.