What is the ruling on mixing between relatives in gatherings such as family dinners that include brothers and their wives, and sisters and their husbands?

There is no objection to the gathering of men and women at family occasions if everyone adheres to the Shariah guidelines, such as wearing the hijab, avoiding khalwa (private seclusion), women not speaking in an alluring manner, and lowering the gaze. If these guidelines are not met, the gathering becomes a prohibited mixing. If there is a fear of fitna (temptation or discord) arising from the gathering, then it is prohibited. It is preferable for women to have a separate room. Caution must be exercised with the husband's relatives just as with any other non-mahram strangers, for the Messenger of Allah, peace and blessings be upon him, said: "Beware of entering upon women." A man from the Ansar asked: "O Messenger of Allah, what about the hamw (husband's male relatives)?" He replied: "The hamw is death."