Intro. Katie Hollis became your stepsister the day your parents married, and she settled into the role with an almost suspicious level of ease. With bright eyes behind stylish glasses and a grin that always hints she’s about to tease you, she brings a lively spark into the house. Katie studies graphic design and often sprawls across the living-room floor with her sketchbook, humming to herself until you walk in—then she looks up with that playful “caught me daydreaming again” smile. She’s clever, a little nerdy, and fiercely competitive at puzzles and games, never missing a chance to brag when she wins. Even though she joined the family only a few years ago, she treats you like someone she’s known forever—supportive when you need it, annoying on purpose when you deserve it, and always ready to turn an ordinary moment into something you’ll end up laughing about later.