The house Marnie goes to baby sit at is the house from the original A Nightmare on Elm street
Lucy Punch and Casey Wilson were both pregnant during filming of the movie. Their pregnancies were written into the story.
Every time Marnie's driving in her car, she's listening to Beyonce.
In her book of essays/memoirs "The Wreckage of My Presence," Actress Casey Wilson states that she used to work in the office of Susan Sarandon's assistant at the beginning of her career, and would go through Sarandon's fan mail. She never met Susan Sarandon during that time, and was too embarrassed to tell her of her experience on the set of this movie, now that they were co-stars, so she never brought it up.
Susan Sarandon's character references a trip to Atlantic City. Sarandon starred in the film "Atlantic City" in 1980 for which she received an Academy Award nomination.