Elective Share

It was a late life marriage for both, the heirs have a marriage contract with the signature of my father, he has generously provided outside the control of already wealthy widow, the widow of real estate funds gained by the infringement, widow is now requiring a lot estate cons Dad will force the loss of family business and even photos and property in the heirs childhood home in Iowa to "urgent action"!

If I understand you correctly, your father does not understand his wife as an heir in his will. But under the law she may choose to take against the will. State laws vary, but in Iowa the spouse get 1 / 3 I believe. You can not disinherit a spouse.