Is it permissible to converse and eat with one's brother's wife, while she is covered (nothing showing but her face and hands), in the presence of her husband?

There is no harm in speaking with one's brother's wife out of necessity, provided there is no fear of temptation. However, it is not permissible to eat with her due to their intermingling. The prohibition intensifies if she uncovers her face and hands, because the preponderant opinion is that it is not permissible to look at them or for them to be uncovered. This ruling applies to young women and those in a similar category. As for an elderly woman who is not desired, it is permissible to eat with her even if she uncovers her face.