Looking for Birth Mother

Helping out a friend, Minnie Hall, looking for her birth mother. Minnie was adopted in Athens in March of 1956 at 14 months of age. She was supposedly born in Athens on 20 January 1955. Her birth mother's name is listed as Anna Anastassopoulos/Anastasopoulos (Anna's father's name was listed as J. Anastassopoulos/Anastasopoulos). Anna would have been about 19 years old in 1956. Minnie's birth name was Angelika/Angeliki Anastassopoulos/Anastasopoulos. Minnie was adoopted by an American couple (adopted father was in the military). If anyone recognizes these names, or could help point me in the right direction, it would be greatly appreciated. Thanks!