Fitness instructor Julia is down on her luck, trying to make her baby boot camp a thriving business. To make ends meet, she becomes a part-time nanny for a single widowed father. Trouble is, she knows nothing about taking care of children.
- Babies Ever After: Julia ends the movie married to Scott, thus becoming stepmother of his two children. In addition, she's pregnant.
- Death by Childbirth: Averted with Scott's late wife; she didn't die giving birth to Mattie, but her pregnancy was sort of the cause of her death. Halfway through her pregnancy, it was discovered she had cancer, and she refused treatment, choosing to save her unborn child over herself. By the time Mattie was born, it was too late to treat the wife.
- Instant Birth: Just Add Water!: Happens twice, and literally in one case - Julia's sister Gwen ends up giving birth in her pool.
- Kids Play Match Breaker: Not wanting Scott to replace her late mother, Charlotte hides her baby sister away and tells her father Julia lost her, to make her look like a bad nanny and get her fired, and away from Scott.
- Magical Nanny: Julia swoops in to help Charlotte and Mattie, and helps fixes the former's problems with her father.
- Marry the Nanny: Scott does by the end of the movie, once he and Julia have admitted they've fallen in love with each other.
- Missing Mom: Scott's wife - Charlotte and Mattie's mother - died a few years prior to the start of the movie.
- Parental Substitute: Julia is this to Scott's daughters, Charlotte and Mattie, once she settles in as their nanny.
- Screaming Birth: Gwen proceeds to scream a lot when she's in labor, as does Julia's client when she goes into labor during class.
- They Do: Julia and Scott marry at the end of the movie.