Is a girl required to cover her face if her work—which is her sole source of livelihood—prevents her from doing so?

Covering the face is obligatory for a woman, and it is not permissible for her to uncover it except before her husband or a mahram. It is not permissible to continue in a job that necessitates neglecting this obligation, nor to reside in a foreign country without a mahram. Residing in lands of kufr (disbelief) is forbidden by Islamic law, based on the Prophet's (peace be upon him) saying: "I am innocent of any Muslim who resides among the polytheists." Therefore, migration (hijra) is obligatory to preserve one's religion and attain Allah's pleasure.