All Praises are Due to Allah
The divorce of a Muslimah from her husband is an affair which is loathsome to Allah and not a praise worthy event. This is due to the problems and possible evils. However, if there is a situation in the marriage life taking place between the man and the women, due to a defect or defects in one or both of them, such problems of deen, bad character, sickness, or a defect such as being sterile or similar. Then out of the mercy of Allah, seeking divorce is permissible. In this case, it is okay and there is nothing prohibited in seeking a divorce.
The thing which is prohibited is a wife seeking a divorce from her husband for no reason of the shariah. There is serious promise made for seeking a divorce without a valid reason. It is reported in the hadith of the Prophet (peace and blessings of Allah be upon him), "If a women asks her husband for a divorce, for no reason, then the smell of paradise is forbidden for her". (At-Tirmidhi narrated it. He said this is a hasan hadith. Sunnah At-Tirmidhi #1187.)