Praise be to Allaah.
It is not
permissible for you to treat your wife’s brother’s wife as your sister,
because she is not one of your mahrams. So it is not permissible for her to
appear before you without proper hijab, and it is not permissible for you to
be alone with her, or to shake hands with her, or to look at her, or to
speak to her except from behind a screen, when there is no fear of fitnah
(temptation). Allaah has forbidden the believing women to show their
adornment except to specific people. Allaah says (interpretation of the
to reveal their adornment except to their husbands, or their fathers, or
their husband’s fathers, or their sons, or their husband’s sons, or their
brothers or their brother’s sons, or their sister’s sons, or their (Muslim)
women (i.e. their sisters in Islam), or the (female) slaves whom their right
hands possess, or old male servants who lack vigour, or small children who
have no sense of feminine sex. And let them not stamp their feet so as to
reveal what they hide of their adornment. And all of you beg Allaah to
forgive you all, O believers, that you may be successful”
You are not one of the
people mentioned in the aayah, so this ruling does not apply to you. And
Allaah knows best.
question no. 5538.