Young Katie (Chloe Csengery) is one of the most known characters of Paranormal Activity 3 where she lives with her mother Julie (Lauren Bitner) and with her mum's boy friend Dennis (Crist Smith) and with her sister Kristi (Jessica Tyler Brown) they live happiley until hunting begins when Krist (Jessica Tyler Brown) finds a friend called Toby that is a ghost known as the child of Bloody Marry.

Young Katie is played by Chloe Csengery.