Muslim woman’s hijaab in front of kaafir women
Question

                What are the things that a Muslim woman may uncover in front of a kaafir woman, such as a Buddhist woman for example? Is it true that she is not allowed to uncover her face?
Praise be to Allah.
    The correct view is that a woman may uncover what is above 
    the navel and what is below the knees in front of another woman, whether she 
    is a Muslim or a kaafir. As for the area between the navel and the knees, 
    this is ‘awrah and is to be covered in front of everyone. No woman should 
    see this area of another woman, whether she is Muslim or non-Muslim, related 
    to her or not related; the same applies to the ‘awrah among men (i.e., no 
    man should see the ‘awrah of another man). A woman may see the chest, head, 
    shins, etc., of another woman; similarly a man may see the chest, shins, and 
    head of another man. With regard to the view of some scholars, that a 
    believing woman should not uncover in front of a kaafir woman, this view is 
    superceded by the more correct of the two scholarly views, because at the 
    time of the Prophet  (peace and blessings of Allaah be upon him), Jewish 
    women and also idol-worshipping women used to enter upon the wives of the 
    Prophet  (peace and blessings of Allaah be upon him) for various 
    reasons; it is not narrated that they used to wear hijaab in front of them, 
    and they are the best and most pious of women.