There is no clear evidence that forbids women from sitting together with their husbands when receiving guests.
There is clear evidence that a man is forbidden from being in seclusion with a woman who is not his wife or near relative. The Prophet (peace be upon him) said: “No man left alone in one place with a woman without Satan being the third of them”.
Also, there is clear evidence that the woman is forbidden to be soft and seductive of speech while talking to men. Allah says: “Be not too complaisant of speech, lest one in whose heart is a disease should be moved with desire: but speak a speech (that is) just” [Sûrah al-Ahzâb: 32].
There is evidence that the woman may not sit with unrelated men while wearing strong perfume. The Prophet (peace be upon him) said: “Any woman wears perfume then passed by some people to let them find her scent, then she is being a temptress.”
There are clear evidences that the woman should not wear flimsy clothing in front of men. Her clothing should not be scanty or transparent. It should be wide and not reveal the size and shape of parts of her body and it should not be an ornament in itself.
If a woman abides by the Islamic commands and prohibitions and observes these set conditions precisely, then she may sit with the guests of her husband in his presence.
However, the unrelated men and women should avoid sitting immediately next to one another. The guests may all talk together respectfully without the men and women becoming overly familiar with each other or flirtatious.
At the same time, any woman who chooses to refrain from sitting with her husband’s male guests for the sake of her own peace and comfort is doing what is good for her. No one should argue with her or disrespect her feelings. No one should describe her as an extremist.
At the same time, if a woman sits with her husband’s male guests while abiding by the above stated conditions and observing her full modest dress, then no one would have any right to call her a loose or immoral woman.
And Allah knows best.