Yes, wife can divorce in this manner, if she has been delegated in the nikanama (marriage contract form) the said right is called Talak-e-Tafweez (delegated powers of divorce). The husband may delegate the right to divorce while contracting marriage as per paragraph 18 of the Nikahnama, then the wife has a right to divorce, otherwise it is the exclusive right of the husband. But if wife has no such right and she wants dissolution of marriage then she can file a suit for the “Dissolution of Marriage” on the basis of Khula or seeks divorce both through intervention of the court.
This topic has now been dealt with in depth at the link below
Can a wife Divorce her husband in Pakistan? (Column 18 Nikahnama)
Other Useful Links on Khula, Marriage (Nikah), Divorce and Custody are as follows:
A Primer on Child Custody, Interim Custody , Visitation and Guardianship as per Pakistani law
