This undated image from the film "Gone with the Wind" provided by New Line Cinema shows, from left, Ann Rutherford, Vivien Leigh and Evelyn Keyes. Rutherford, who played Scarlett O'Hara's sister Carreen in the 1939 movie died at her home Monday in Beverly Hills, Calif. She was 94. (AP)

Ann Rutherford, a wholesome supporting actress in Hollywood films of the 1930s and 1940s, notably as Scarlett O’Hara’s youngest sister in “Gone With the Wind” and as Mickey Rooney’s loyal sweetheart in the Andy Hardy movie series, died June 11 at her home in Beverly Hills, Calif. She was 94 and had heart ailments.

The death was confirmed by a friend, actress Anne Jeffreys.

A pert brunette with strikingly big brown eyes, Ms. Rutherford was the quintessential girl-next-door in dozens of films. Time magazine once described her as having “two of Hollywood’s gentlest shoulders and most innocent eyes.” Despite the general sweetness of her screen persona, she proved convincing as Danny Kaye’s henpecking fiancee in “The Secret Life of Walter Mitty” (1947).

While the prominence and quality of her roles fluctuated, Ms. Rutherford was a sensitive performer at light comedy and melodrama. She appeared in high-end productions such as “Pride and Prejudice” (1940), starring Laurence Olivier and Greer Garson, and low-budget westerns opposite the warbling cowboy Gene Autry.

“I was Gene Autry’s first leading lady and the only one he ever kissed,” she once quipped. “After that, he kissed his horse.”

The daughter of entertainers, Ms. Rutherford made her screen debut in 1935 as the star of the low-budget drama “Waterfront Lady.” Two years later, Ms. Rutherford was signed by the most prestigious studio in Hollywood, Metro-Goldwyn-Mayer, and was cast in the Andy Hardy series.

They starred Rooney as an all-American teenager who learns lessons in love and friendship — often at the foot of his understanding father, a small-town judge fond of “man to man” talks. The films, with their idealized vision of American small-town life, were a box-office sensation during the Depression and World War II.

The series earned more than $75 million for MGM (when movie tickets cost about 25 cents) and made Rooney the world’s biggest movie star for three years.

Portraying Polly Benedict, Ms. Rutherford appeared in more than 10 of the films, from “You’re Only Young Once” (1937) to “Andy Hardy’s Double Life” (1942). As Hardy’s long-suffering, socially proper flame, she competed at times for the young man’s affections by more physically bewitching starlets such as Esther Williams, Lana Turner and Donna Reed.

Ms. Rutherford later recalled that she was not excited initially about taking the part. Perhaps apocryphally, she told interviewer Richard Lamparski that for much of the run, she had to stand in a hole so she would not tower over the diminutive Rooney.

As her clout rose at MGM, Ms. Rutherford said she fought for the role of Carreen — the youngest of the three O’Hara sisters in “Gone With the Wind” (1939) — despite studio chief Louis B. Mayer’s objections that it was a “nothing part” at a rival studio.

A fan of the Margaret Mitchell novel, Ms. Rutherford insisted on being loaned out to producer David Selznick. She said Mayer relented after she uncharacteristically burst into tears in his office. “He was usually the emotional one,” she told the Los Angeles Times in 2010. “All it needed for me was to burst out crying. He said, ‘Get in your car and go over to the studio.’ ”

Ms. Rutherford became a gregarious fixture at anniversary screenings of the Civil War epic and was besieged by autograph seekers. “That ‘nothing part’ turned my golden years into platinum,” the Times quoted her as saying.

Therese Ann Rutherford was born Nov. 2, 1917, in Canada; various biographical sources say Vancouver or Toronto. Her father was an operatic tenor, and her mother was an actress.

The family settled in Los Angeles, where Ann’s early work as a radio actress led to starring roles in low-budget westerns with John Wayne and Autry.

Later at MGM, she toggled between dramas such as “Of Human Hearts” (1938) with James Stewart and Walter Huston, and froth such as “Dancing Co-Ed” (1939) with Lana Turner and the Artie Shaw Band. She played the spirit of Christmas past in “A Christmas Carol” (1938) and was Lydia Bennet in “Pride and Prejudice,” based on the Jane Austen novel. She also was a helpmate to Red Skelton in the comedy thriller “Whistling in the Dark” (1941) and its two sequels.

Mayer sold Ms. Rutherford’s contract to 20th Century-Fox in 1942, and she played the wife of a trumpeter (George Montgomery) in “Orchestra Wives” (1942), starring the Glenn Miller Band. Among her best films before retiring in 1950 was “Adventures of Don Juan” (1948), opposite Errol Flynn.

Her first marriage, to department store heir David May, ended in divorce. In 1953, she married William Dozier, a television producer whose credits included the “Batman” series. He died in 1991. Survivors include a daughter from her first marriage.

Ms. Rutherford was shrewd about her finances after having seen once-marquee actors reduced to minor roles in low-budget films. She told Lamparski that she often took the bus to MGM, even while earning $500 a week. She said that when the studio once threatened to cancel her contract over a pay raise dispute, she took out her bankbook, showed her ample savings and called its bluff.