A confusing situation. The records show Wnthrop married Elsa Johnson in 1938 and Peggy Baker in 1943, but the death record for daughter Susan shows her mother as Ilene (sic) Johnson and her birth date as 1950. Winthrop's 1943 marriage license to Peggy Baker states he is divorced, but the 1950 census shows him living with Elsa. Also, Elsa is buried in the Walnut Hills Cemetery in Brookline, Mass., where many other Sargent family are also buried. Peggy married her second husband Dec. 31, 1951. The license for this marriage shows her name as Peggy Joyce Baker Sargent. So it seems Winthrop and Peggy divorced prior to the April 3, 1950 census date which has him and Elsa living together. Nothing indicates Winthrop and Elsa ever remarried, other than the 1950 census which does state that they are married.
Timeline:
1938: Marries Elsa Eileen Johnson
1939: Son Winthrop born
April 1940: Living with Elsa in census
Divorces Elsa sometime between April 1940 and 9/22/1943
9/22/1943: Marries Peggy Joyce Baker
Divorces Peggy sometime between 9/23/1943 and April 1950
Remaries Elsa sometime between 9/23/1943 and April 1950
April 1950: Living with Elsa in census and listed as married
September 1950: Daughter Susan born
1951: Peggy marries Herbert Dyckman
1955: Peggy and Herbert divorce
1956: Daughter Susan dies