Mary Jo Kopechne was born in Pennsylvania but lived in East Orange* during most of her childhood years and attended Our Lady of the Valley High School in Orange from 1954 to 1958. Her younger cousin, Georgetta Potoski of Pennsylvania, recalled in a 2009 interview that "she spent many summers [with Mary Jo] at the Kopechne home in East Orange, N.J."
Above: from the 1957 Our Lady of the Valley High School yearbook; It was Miss Kopechne's junior year
Below: from the 1962 yearbook for Caldwell College, Miss Kopechne's graduation photo
*Exactly where in East Orange has not been verified, but possibly the Elmwood Park area.