NEW YORK—Patricia Hitchcock O’Connell, the only child of Alfred Hitchcock and an actor herself who made a memorable appearance in her father’s “Strangers on a Train” and championed his work in the decades following his death, has died at age 93. Hitchcock died Monday in her sleep at home in Thousand Oaks, California, her daughter Tere Carrubba said Wednesday. She died of natural causes, said Carrubba. “She was always really good at protecting the legacy of my grandparents and making sure they were always remembered,” said Carrubba, one of Patricia Hitchcock’s three daughters. “It’s sort of an end of an era now that they’re all gone.” Known to many as Pat Hitchcock, she was born in London to Alfred Hitchcock and Alma Reville Hitchcock in 1928 and spent much of her life in and around the family business. During her childhood, Alfred Hitchcock directed such classics as “The 39 Steps,” …