Despite Molly's invisibility, the characters still track her movements and make direct eye contact. They even react to her motions I.e high fives and hugs without and verbal prompt.
Alex Désert played Eli Williams on the sitcom Boy Meets World (1993), whereas Rowan Blanchard is the star of the Boy Meets World sequel series Girl Meets World (2014). Désert played Cory Matthews' teacher and Blanchard plays Cory's daughter, Riley.
Paris Berelc is the fourth Actress from a Disney XD series to star in a Disney Channel Original Movie. The other two being Kelli Berglund in How to Build a Better Boy (2014) and Spencer Boldman in Zapped (2014) and Olivia Holt (prior to starring in I Didn't Do It (2014) on Disney Channel) in Girl Vs. Monster (2012).
Based on the novel "My Invisible Sister" by Beatrice Colin and Sara Pinto.
Originally Coug had a younger sister named Karen, played by Francesca Capaldi. It's not known why she wasn't featured in the Final Film.