Can a woman talk to Mahram man, or come in front of them, during the first 40 days of her husband's death?Please advise, with a Hadeeth, or two, if possible.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

A woman in her waiting period is like a woman who is not in her waiting period in dealing with her Mahaarim (non-marriageable relatives). She can talk to them, remove her Hijab and show what is permissible for her to show in front of them exactly as if she is not in her waiting period.

Allaah knows best.