Does a spouse have to let the other know if they sell their interest of a will?

When my mother was alive she filed a P.O.A. on my father. He then filed for divorce. He financed his divorce attorney and the other siblings Probate Attorney (same lawyer) by selling his portion of the will. There were and are 2 wills. My mother asked over and over again, where he got the money to file. Legally his lawyer, other siblings etc. This was while my mother was alive. He did not make this public to the Divorce Court and to Probate. When Probate was over he pulled the divorce and waited until my mother passed and then gave her portion of the estate to my cousin who financed all this? Didn't my mother have a right to know and have a right to change her portion of the will?