"It Is Permissible for the Husband to Forbid His Wife from Visiting a Specific Woman"
Translated from the Muslim Brotherhood-linked European Council for Fatwa and Research.
Answer: It is permissible for the husband to forbid his wife from visiting a specific woman--Muslim or non-Muslim--if he fears that there is mischief behind it, or harm for the woman or his children, or for the life of their marriage.
The man is the head of the family and its guardian, and he must protect it from anything which may expose it to danger, even if it is only a likely danger. One of the established rules of Islam is the following: preventing evil takes precedence over obtaining one’s interests. Our counsel is this: the man should not act arbitrarily in these matters, nor be suspicious where no suspicion is warranted, and confine his wife to isolation, like a prison, and forbid her from contacting anyone she knows, as a result of suspicion and conjecture. The Most High said: “O ye who believe! Avoid suspicion as much (as possible): for suspicion in some cases is a sin” [Qur’an 49:12]. Also (the Prophet) (peace be upon him) said: “Beware of suspicion, for suspicion is the worst of false speech.”
Islam does not command the Muslim man and woman to cut off contact with all non-Muslim men and women, especially the People of the Book.The Almighty said: “Allah forbids you not, with regard to those who fight you not for (your) Faith nor drive you out of your homes, from dealing kindly and justly with them: for Allah loveth those who are just” [Qur’an 60:8]. Allah does not forbid being good to them and treating them fairly. Fair means just, and good means kind, which is above justice. The shari’ah has expressed that the most sacred of relationships among all creatures is that of children toward their parents, which is kindness.
European Council for Fatwa and Research, August 22, 2009, http://www.e-cfr.org/ar/index.php?ArticleID=443.