Praise be to Allah.
If the husband is giving his wife her rights as prescribed in sharee’ah, then it is haraam for her to ask him for a divorce, because the Prophet (peace and blessings of Allaah be upon him) said: “Any woman who asked for a divorce for no reason, the fragrance of Paradise is forbidden to her.” Narrated by al-Tirmidhi, 1187; Abu Dawood, 2226; Ibn Maajah, 2055; classed as saheeh by al-Albaani in Saheeh Abi Dawood).
What is meant by the words “for no reason” is without any urgent situation which makes it hard for the marriage to continue.
If the wife is being harmed and the situation is too difficult for her because of the husband’s falling short in giving her her rights, or his withholding her rights from her, or because of his bad treatment and other similar reasons, then she has the right to ask for divorce, and she may refer to the qaadi and tell him what is happening, and he in turn can ask the husband to give her her rights or to divorce her.
If she has found out that he has some bad characteristics, he should not hasten to ask for a divorce, rather she has to be kind to him and advise him in the way that is best, and help him to change his character for the better. He acknowledges the way he is and has promised to change. This is a positive step on the husband’s part and it is the first step in dealing with the problem. The wife should help her husband to do good. If every wife wanted a divorce when he was quick to get angry or transmitted some words that were spoken between him and his wife, or other mistakes, there would be no household that was not broken up and its members scattered.
And Allaah knows best.