Is it permissible to attend a Thanksgiving feast at the husband's family's home if the occasion is for holiday and affection?

It is not permissible to participate in the celebrations of non-Muslim holidays. Nor is it permissible to eat what is slaughtered or prepared for the sake of these holidays, whether it be turkey or anything else. This includes celebrating Christmas with Christians, as accepting their invitation or eating their food is considered an encouragement and an affirmation of their innovations. One should apologize to them with wisdom and in a polite manner.