What Is The Law For Women's Divorce In Islam?

From a reading of the Quran we learn that God does not favour divorces and in fact encourages the continuation of marriage. God has imposed prohibitions on certain category in marriage. However for those who comes to know of these prohibitions afterwards are commanded not to break existing marriages - see 4:22-23.
Divorce must be resorted to only in exceptional circumstances. The laws relating to divorce together with the relevant verses from the Quran are given below:

Appoint an arbitrator
[4:35] If a couple fears separation, you shall appoint an arbitrator from his family and an arbitrator from her family; if they decide to reconcile, GOD will help them get together. GOD is Omniscient, Cognizant.

Wait 4 months cooling off before divorce

[2:226-227] Those who intend to divorce their wives shall wait four months (cooling off); if they change their minds and reconcile, then GOD is Forgiver, Merciful. If they go through with the divorce, then GOD is Hearer, Knower.

If the estranged couple chooses separation they must go through with it equitably. There must be two equitable witnesses witness the divorce before GOD

[65:2] Once the interim is fulfilled, you may reconcile with them equitably, or go through with the separation equitably. You shall have two equitable witnesses witness the divorce before GOD. This is to enlighten those who believe in GOD and the Last Day. Anyone who reverences GOD, He will create an exit for him.