Is a wife obligated to remove her niqab in a Western country out of fear of its effect on her children, especially if one of them needs intensive treatment and extensive interaction with society?

Covering the face is obligatory according to the more preponderant opinion of scholars. Therefore, it is not permissible to uncover it merely due to an imagined harm. However, if harm is highly probable and cannot be averted except by uncovering the face, then there is no sin in uncovering it. If the cause of fear is removed, it becomes obligatory to resume covering the face. One should also be keen not to go out except when necessary.