The length of time that a Barbie movie is in theaters can vary depending on the specific movie and its popularity. Generally, animated children's movies like those featuring Barbie may stay in theaters for around 4-6 weeks, but this can change based on factors such as box office performance, competition from other films, and the movie's overall reception. It's always a good idea to check local listings or theater websites for the most up-to-date information on showtimes and how long a specific movie will be playing.