What are the etiquettes of dealing with domestic workers, especially if the worker is a foreign Christian whose mother is Muslim and father is Christian, with a desire for her to embrace Islam? And is it obligatory for the veiled mother to uncover her face in front of her?

The mother is not obliged to cover her face and hands in front of a female servant, whether Muslim or non-Muslim. However, what may be uncovered in front of a Muslim woman differs from what may be uncovered in front of a non-Muslim woman. The preponderant opinion is that a Muslim woman may uncover for a non-Muslim woman what is usually visible during service, such as the face, head, hands up to the elbows, and legs up to the knees. This is more applicable to an elderly woman. As for the etiquette of dealing with a female servant, it is the same etiquette applied to anyone a Muslim interacts with. A man who is not a mahram must treat the female servant as a non-relative; he should not look at her or be in seclusion with her. In general, servants should be treated kindly.

Two notes: 1. If the female servant is underage, her Islam is determined by that of her mother. 2. A Muslim woman is not permitted to marry a non-Muslim man, and if such a marriage exists, it must be annulled.