a child was adopted out - now is claiming she has legal right to her deaceased mothers estate and is removing everything

Daughter was adopted out at birth. The daughter, since becoming an adult has had contact with the biological mother. The mother passed away, supposedly without a will (that is another matter), the daughter got a locksmith to open up the mother's home, has taken her truck and is removing items from the home...and not allowing anyone else near it. This is in Oklahoma. Concern is raised as she has told several freiends that the daughter and the descendants sister are not to have a thing...that there is a will...the daughter got into the safe deposit box and removed everything from it...which is where we were told the will is. Does the adopted out daughter have any legal rights ... or ... as we understood ... would it go to the surviving sister or nephew. This case may become a million dollar estate in the end due to inheritance and stocks involved.