A Code of Practice For Muslims in the West : Women's issues » General Rules
Fatawa of Ayatullah al Uzama Syed Ali al-Husaini Seestani
450: It is not permissible for a woman to expose the top part of her feet to a non-mahram onlooker. However, she is allowed to keep her feet —top as well as sole— exposed during salãt, if she is in a place where she is immune from the looks of a non-mahram person.
478: Question: A Muslim woman wears high heel shoes that hit the ground in such a way that it draws attention. Is she allowed to wear it?
Answer: It is not permissible, if it is intended to draw the attention of non-mahram men to herself, or if it generally causes temptation [for committing sin].
489: Question: Is a woman allowed to wear trousers and take to the streets and markets?
Answer: It is not allowed, if it reveals the contours of her body or would normally arouse temptation.