The main reason Jack Nicholson agreed to appear in this movie: he wanted to work with Meryl Streep.
Meryl Streep was pregnant in real life during the making of the movie.
Meryl Streep admitted on The Tonight Show Starring Jimmy Fallon (2014) that her daughter Mamie Gummer was credited under the name "Natalie Stern". Meryl said that she had this done so that there would be no photographs of her daughter, because she was only around eighteen months old at the time of filming.
This movie doesn't make this explicit, but in real life, screenwriter Nora Ephron had been so upset by her husband's infidelity that she went into labor prematurely.