Woman uncovering part of her body in front of other women
Question

                Is it permissible for a woman to uncover any part of her chest, or what is called the ribs or her forearms or legs in front of other women?.
Praise be to Allah.
    As for the forearms, there is nothing wrong with uncovering 
    them in front of women, and there is also nothing wrong with showing the 
    neck and head in front of other women, but we offer some advice to our 
    womenfolk in the hope that Allaah may benefit them thereby. We say: the more 
    covering the clothes are, the better it is for them, and we tell them not to 
    follow whatever may be in these magazines and copy what is shown in them, 
    because that leads women to resemble kaafir women whether they want to or 
    not. The more covered women are, the better. Shaykh al-Islam Ibn Taymiyah 
    (may Allaah have mercy on him) stated that the women of the Sahaabah wore 
    garments that covered them from the hand to the ankle, and this is what is 
    best. There is nothing wrong if the calves show, but we are not suggesting 
    that she wear a dress that comes down only to the knees, because there may 
    be cause for concern about that, since may go further than that and shorten 
    their dresses to above the knee. But if a woman lifts up her garment to do 
    something and her sister sees her do that, there is nothing wrong with it. 
    But if the garment is designed to come down only to the knees, we do not 
    think that is right, rather we think that it should come down to the ankles. 
    End quote. 

    Shaykh Muhammad ibn ‘Uthaymeen (may Allaah have mercy on 
    him).