Since there’s no such thing as “carolwood”, we must assume that “Carol” refers to a person. My educated guess: Caroline Letts (1836-1912), whose son Arthur owned The Broadway department store… and the land that would become Westwood and Holmby Hills. The English-born Mrs. Letts joined her son in L.A. in 1900. After Arthur Letts died in 1923, his son Arthur Jr. and the Janss Investment Co. – Harold Janss was married to Arthur Sr.’s daughter Gladys – subdivided this land. Harold and Gladys Janss themselves lived on Carolwood, as did Arthur Letts’s widow and her second husband. The street’s more famous residents included Walt Disney, Frank Sinatra, and Michael Jackson.