Is it permissible for a non-Muslim woman to look at a Muslim woman without a hijab, and does this apply to the non-Muslim mother of the husband?

"Scholars have differed on the ruling concerning a woman uncovering her hijab (definition) in front of a non-Muslim woman. The reason for this disagreement stems from the interpretation of the verse in Surat An-Nur: ﴿...and not expose their adornment except to their husbands...or their women.﴾ The preponderant opinion is the permissibility for a Muslim woman to appear before a non-Muslim woman, as long as she does not fear that the latter might describe her to her husband or a non-mahram (definition) man. In this regard, there is no difference between a non-Muslim woman and a sinful Muslim woman. Among the evidences that support this permissibility is the narration of 'Aishah (may Allah be pleased with her) with the Jewish woman. Sheikh Ibn Baz permitted this, and Sheikh Ibn 'Uthaymeen stated that a Muslim woman may show to a non-Muslim woman what she shows to her mahrams, which includes places of adornment or places of ablution."