The filmmakers have said in interviews their story is based on a 2001 National Public Radio "All Things Considered" report about two women in the Seattle suburbs who started a biohazard removal/cleaning service. They are best friends, not sisters.
The vacuum and cleaning supply store is the same establishment used as Best Quality Vacuum, run by Robert Forster's character as a front business in both Breaking Bad (2008) and El Camino (2019). The actual location on 4th Street in Albuquerque is a furniture store.
A kiss scene was filmed between Norah (Emily Blunt) and Lynn (Mary Lynn Rajskub) but cut from the finished film.
Eric Christian Olsen filmed several scenes as Norah's boyfriend Randy, and most of them were cut. He only appears in the party scene, where Norah says, "He's not my boyfriend" and when he and Norah have sex as she sees a news report about an accident.