Miss Lulu Bett is a story about the Deacon family, residents of a typical American small town. Dwight Deacon is the obnoxious, narrow-minded patriarch, Ina Deacon is his rather lazy wife, and Diana and Monona are their two spoiled daughters. Grandma Bett, Ina's mother, lives with the family and has a rather unfriendly relationship with her son-in-law.
The central character is the eponymous Miss Lulu Bett, Grandma Bett's daughter and Ina's sister. Lulu lives with the Deacons as well, but instead of a guest she functions as a servant, and in fact more like a slave, cooking and cleaning for the entire Deacon family while having no time for herself. The unexpected arrival of Dwight's charming, roguish brother Ninian, however, offers a chance for escape, especially after Ninian takes a fancy to Lulu. There's also Cornish, the mild-mannered schoolteacher who is another admirer of Lulu.
Miss Lulu Bett started out as a 1920 novel by Zona Gale. She then adapted it into a play which won the Pulitzer Prize for drama (Gale becoming the first woman to win a Pulitzer). Shortly after that it was adapted into a 1921 film which starred Lois Wilson as Lulu and was directed by Cecil B. DeMille's brother William, who himself had a pretty successful directing career during the silent era.
- Accidental Marriage: Everybody's bored at a fancy dinner when Ninian, to liven things up, jokingly asks Lulu to marry him, and she jokingly accepts. They are both shocked when Dwight tells them that because he's a justice of the peace and they made a verbal pledge in his presence, their marriage is real and legally binding.
- Adaptational Alternate Ending: In the novel, Lulu marries Cornish. All the adaptations end differently:
- The original ending of the play has Lulu blow town, but not before extending a hope for a Maybe Ever After towards Cornish.
- In the Revised Ending for the play, Ninian shows up again and Lulu takes him back.
- The film went with still a different ending in which Lulu leaves the Deacon house, but stays in town, where she and Cornish declare their love for each other.
- Call-Back: In the original ending to the play, and only the original ending. Lulu tells Ninian she is single "by choice!". At the end she tells Dwight she is leaving "by choice!"
- Double Standard: Ninian asks Lulu if she's a Miss or a Mrs., and Lulu parries by asking him if he's a Miss Mister or a Mrs. Mister. Ninian laughs, noting that a man's name doesn't reveal if he's married.
- Exact Words: Monona is irritating Dwight with her bad piano playing, so Dwight says "Keep your hands off the piano!" Monona proceeds to play the piano with her elbows.
- Gossipy Hens: The mean old ladies—and the sleazy men—who gossip about Lulu after she comes home from her brief marriage to Ninian.
- Hollywood Law: Hard to believe any jurisdiction anywhere would regard a marriage proposal made and accepted in jest as binding.
- Hypocritical Humor: "I won't eat another bite in that man's house!", says Grandma Bett, who then promptly starts scarfing food out of the kitchen after stalking out of the dining room.
- Jerkass: Dwight is mean and nasty, insulting Lulu, taking advantage of her free labor, blaming her for the mess with Ninian.
- Leaving You to Find Myself: In the original ending to the play, Lulu says goodbye to everyone, both her Jerkass family and her admirer Cornish, going off to live independently for a while.Mrs. Bett: Where you goin' now, for pity sakes?
Lulu: Away. I thought I wanted somebody of my own. Well, maybe it was just myself.
- The movie includes a scene similar to this, but also features an epilogue in which Lulu reunites with Cornish after getting a job at a bakery.
- Letting Her Hair Down: The opening scenes of the movie show beauty pageant winner Lois Wilson made up as dowdily as possible, with her hair pinned up in a tight bun. With her day of drudgery finally done, she takes out the pins, and reveals long, luxurious hair. Naturally, Ninian shows up right after this.
- Oops! I Forgot I Was Married: Ninian waits a week to tell poor Lulu that he was married 15 years ago and his wife is, as far as he knows, still floating around out there somewhere. A mortified Lulu leaves him and goes home.
- "The Reason You Suck" Speech: The climax, in which Lulu laughs in Dwight's face and tells him how much she hates him, and that there's no way she'll continue to be their unpaid servant.
- Revised Ending: The original ending of the play, the one that won Gale the Pulitzer, has Lulu blow town, but not before extending a hope for a Maybe Ever After towards Cornish. This proved controversial so Gale wrote a different ending for the play in which Ninian shows up again and Lulu takes him back.
- Tantrum Throwing: The deeply satisfying climax of the film has Lulu stalk out of the Deacon home after contemptuously refusing Dwight's "forgiveness", but not before wrecking a lot of his dishes and shouting that all her years of unpaid work will pay for them.