Is it possible for a Muslim woman to take of her scarf (Hijab) in front of Christian women?

Praise be to Allah, the Lord of the Worlds; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
The Awrah (those parts which should be covered) of a Muslim woman in front of fellow Muslim women is between the navel and the knee. But the Awrah for the Muslim woman in the presence of non-Muslim woman is the whole body since Allah Says (interpretation of meaning): {And tell the believing women to lower their gaze (from looking at forbidden things), and protect their private parts (from illegal sexual acts, etc.) and not to show off their adornment except only that which is apparent (like palms of hands or one eye or both eyes for necessity to see the way, or outer dress like veil, gloves, head-cover, apron, etc.), and to draw their veils all over Juyubihinna (i.e. their bodies, faces, necks and bosoms, etc.) and not to reveal their adornment except to their husbands, their fathers, their husband's fathers, their sons, their husband's sons, their brothers or their brother's sons, or their sister's sons, or their (Muslim) women (i.e. their sisters in Isl�m), or the (female) slaves whom their right hands possess, or old male servants who lack vigour, or small children who have no sense of the shame of sex.}[24: 31].
The words "Or their women" in the above Aayah means fellow Muslim women. If the looking of a Kafir woman at a Muslim woman is permissible it is not mentioned in this Aayah.
It is proved from Umar (May Allah pleased with him) that he prohibited Women of the Book to enter saunas with Muslim women. The Awrah of a Muslim woman in-front of her (Maharim) unmarriageable relatives is no more than her face, head, hands and feet so it is forbidden for her to show her chest, breast in front of her Maharim. All the mentioned rules apply in normal situations but if she is compelled to disclose her body in front of a non-Muslim for treatment and the like then she can do so. No doubt disclosing her body infront of a non-Muslim woman is easier then disclosing it infront of alien Muslim men.
Allah knows best.