The permissibility of brothers sitting with their wives provided they observe the Islamic covering

Question:
Brothers sit together with their wives in one gathering to drink coffee or for the remembrance of Allah. Is this permissible? And if it is permissible, what is the ruling for those who are not brothers but are in this same situation?

Answer:
The husband of a sister, the wife of a brother, and the like are not to sit with the husband's brother. A woman must not display any of her beauty to her sister's husband, whether her face or anything else. Rather, she must cover herself with the hijab. If she sits with them while observing the hijab, covering herself, and not displaying her adornment, there is nothing wrong with it. If she sits and greets them verbally while observing the Islamic hijab on her face and the rest of her body, there is nothing wrong and no blame on her.
As for sitting while displaying her beauty to them, that is not permissible. This applies even if she is not sitting with them, or if she is in another place. She has no right to display her beauty. Rather, she must observe the hijab from her sister's husband, her husband's brother, her husband's paternal uncle, and all her non-mahram relatives absolutely.