Husband has been given a share in wife’s inheritance when she dies. As long as the wife is alive, her property is hers only and a husband has no share in it unless wife chooses to give him as per her own freewill. Share received by wife from her deceased father’s inheritance is wife’s property now and a husband has no right over it as long as the wife is alive.
After demise of the wife: if she does not have any children, then her husband shall receive one-half of what she leaves and if she has children, then the husband’s share is one-fourth of what she leaves.
For Detail on Islamic Law of Inheritance, please see:
Discussion 10380