The bathroom scene with Frances and Sophie last 28 seconds, yet it required 42 takes to get it right. Greta Gerwig detailed the experience in a NY Times Magazine article in May 2013 titled "I Know I'm Doing the Scene Badly, But I Can't Figure Out How to Do It Well."
Charlotte d'Amboise, who plays the head of Frances's dance company (and whose character describes herself as a former dancer) is in fact a well-known Broadway dancer, with such Broadway shows on her resume as Cats, Chicago, A Chorus Line, and Pippin. She is also the daughter of former New York City Ballet principal dancer Jacques d'Amboise.
Greta Gerwig was raised as a Unitarian Universalist and there's a scene in the film with Greta and her real-life parents that features a visit to the Unitarian Universalist Society of Sacramento church that she and her family grew up attending.