Margaret O'Brien

 Margaret O'Brien, at age six, on set: "When I cry, do you want the tears to run all the way or shall I stop halfway down?"

O'Brien's mother wanted more money for her to play Tootie in the film "Meet Me in St. Louis" (1944). The studio then instead cast the young daughter of a lighting man working on the film, going so far as to even fit her with costumes. They then changed their minds and decided to go ahead and cast O'Brien. O'Brien was playing a scene when that lighting man intentionally dropped a heavy spotlight to the sound stage, narrowly missing the young actress. He was taken away and actually admitted to a mental institution for a time for his deed.

Director Vincente Minnelli was impressed with O'Brien's exceptional acting at such a young age, though he found some of her methods "enervating." Minnelli explained, "Her mother and aunt would whisper to her just before we shot the dramatic sequences and, like the salivating of Pavlov's dog, Margaret would get highly emotional and cry. I often wondered what they said to her to get that reaction. I was soon to learn." Minnelli, according to his autobiography, discovered one of O'Brien's techniques during the scene in which Tootie, upset over the thought of leaving St. Louis, tearfully takes a stick to the snow people in the backyard and violently knocks them down. "Her mother came to me," said Minnelli. "'Margaret's angry at me tonight. She doesn't want me to work her up for the scene. You'll have to do it.' 'But how?' I asked. 'She has a little dog,' her mother replied. 'You'll have to say someone is going to kill that dog.'" Minnelli was reluctant to do something that seemed so harsh, but O'Brien's mother convinced him that it would elicit the emotional response that was needed for her to do the important scene. Minnelli eventually told O'Brien what her mother suggested about her dog, and on cue, the tears began to flow on camera. "She did the scene in one take...mercifully for me...and went skipping happily off the set," said Minnelli. "I went home feeling like a monster...I marvel that Margaret didn't turn out to be one too. That sort of preparation struck me as most unhealthy."

In her mother's defense, years later Margaret O'Brien claimed that the story was false. "My mother would never have allowed that," said O'Brien in 2004. "June Allyson was also a big crier at the studio and so we had a little contest going: Who was the best crier? So all my mother would have to say if I had a hard time crying was that maybe she'd better have the makeup man come over and spray the false tears instead of my crying the real tears, and that would upset me terribly, and then I would cry."

In "Have Yourself a Merry Little Christmas", Judy Garland refused to sing the grim original line, "Have yourself a merry little Christmas, it may be your last," to O'Brien. The line was dropped from the final version of the song.

According to co-star Mary Astor, O'Brien liked to have fun with the prop master. For instance, when shooting a scene at the Smith family dinner table, all of the dishes and utensils had been laid out meticulously. "It was Maggie's favorite form of mischief, when his back was turned," said Astor, "to put things in disorder again, to reverse knives and forks, to put two napkin rings beside a plate. It would drive him nuts. And remember the strong caste system on the sets: she was a star and he was just a lowly property man, so all he could do was to smile and say, 'Please, Maggie dear!' when he'd have liked to have shaken her.