Question: Is it allowed for a woman advanced in age, say 70 or 90 years old, to uncover her face in front of relatives who are not mahram?

Response: Allah says,

"And as for women past child-bearing who do not expect marriage, it is no sin upon them if they discard their (outer) clothing in such a way as not to show their adornment. But to refrain is better for them. And Allah is All-Hearer, All-Knower" (al-Nur 60).

So there is no harm if the menopausal women who are not seeking marriage and are not displaying their adornments uncover their faces in front of non-related men. However, for them to remain covered is still better for Allah has said in the verse,

"But to refrain is better for them."

This is because some of them, when they are seen, may be a source of temptation due to their beautiful faces even though they are elderly and not displaying their adornments. However, if she is going to be having adornments [such as make-up and jewelry], she may not take off her outer covering. Having adornments includes beautifying the face with kohl and so forth.

Shaikh ibn Baz

Islamic Fatawa Regarding Women - Darussalam Pg.263-264