 Her twin sister Emily is played by Megan's real-life twin Kathryn "Kat" Prescott

Katie—along with identical twin Emily—was born in 1992 to Jenna Fitch, a beautician turned wedding planner and Rob Fitch, the gym owner of "Fitch Fitness".Being the older twin by a few minutes Katie is notably more aggressive, controlling, and extroverted in contrast to younger twin Emily's quieter nature.During their childhood she and Emily created a secret language that only they can understand called "Twin Speak".