iona costello , 51 , and daughter emily were going into the city when they were last seen on march 30 near their home in the wealthy seaside village of greenport .
their car was found in a parking garage on 42nd street in manhattan , but the pair , who often went into the city for theater and art museums , left no other trace of their whereabouts .
costello 's adult children have argued that the will granting the estate to iona was improperly executed , according to novick law group .