Additionally, 63 year old Alfred Molina is much older than the real Robert Aldrich's age of 44 at the time. On the other hand, Stanley Tucci is 56 years old and playing 70 year old Jack L. Warner.
1) In the the show, during a dinner, Bette Davis (Susan Sarandon) says to Joan Crawford (Jessica Lange) that she lost her virginity when she was 25. But in 1971, during The Dick Cavett Show (1968), real Bette alleged to have lost her virginity when she was 26 and married.
2) The show changes the date of journal advertisement in which Bette is seeking a job in Hollywood. It was actually published before production of "Baby Jane" starts, the advertisement was kind of a personal joke regarding the situation of aging actresses,.
3) In the Pilot, Robert Aldrich says to Jack L. Warner that he has written the script of "Baby Jane" himself, but in real life the screenplay was written by Lukas Heller.