Can she divorce a husband whom she does not love?

Islam does not want to impose an unbearable burden on women by forcing them to marry a man they dislike, because it wants marriages to be successful, based on compatibility between the partners; there should be common ground between them in terms of physical looks, attitudes, habits, inclinations and aspirations. If something goes wrong, and the woman feels that she cannot love her husband sincerely, and fears that she may commit the sin of disobeying and opposing this husband whom she does not love, then she may ask for a divorce. This is confirmed by the report in which the wife of Thabit ibn Qays ibn Shammas, Jamilah the sister of ‘Abdullah ibn Ubayy, came to the Prophet (sallallahu ‘alayhi wa sallam) and said: “O Messenger of Allah, I have nothing against Thabit ibn Qays as regards his religion or his behavior, but I hate to commit any act of kufr when I am a Muslim. The Prophet (sallallahu ‘alayhi wa sallam) said: “Will you give his garden back to him?” - her mahr had been a garden. She said, “Yes.” So Allah’s Messenger  sent word to him: “Take back your garden, and give her one pronouncement of divorce.”

From: The Ideal Muslim Woman and Her Husband
(An Excerpt from the Book “The Ideal Muslimah: The True Islâmic Personality of the Muslim Woman as Defined in the Qur’ân and Sunnah”)
By  Dr. Muhammad ‘Ali Al-Hashimi
@http://www.wefound.org/texts/Ideal_Muslims_files/herhusband.htm

The Prophet (sallallahu ‘alayhi wa sallam) warned those foolish women who ask their husbands for a divorce with no legitimate reason that they would be denied even the scent of Paradise:

“Any woman who asks her husband for a divorce with no good reason will be deprived of even smelling the scent of Paradise.”