She'd been called different things over the years.
In preschool, she'd been Brownie, because of her love for the desert.
In her middle school years, she'd decided that Katherine was cooler name, and she'd kept up that trend for until high school.
Her mother called her Katie, or Katherine when she was clumsy.
Her dad called her Kitty Cat, and her sister called her Sis, or occasionally Twin. (They weren't twins, but liked to pretend they were.)
In high school, she'd gotten a few nicknames she preferred not to mention, usually doing with her curvaceous body type, and an unfortunate (one time) incident with a football player.
Once she'd joined the FBI, a place of code names and intrigue, she'd been given a new name for almost every undercover case. She was rarely allowed to use the same first name, and never the same surname.
Before 9/11, she'd vacillated between very romantic names like Adriana or Melinda, to plain, boyish ones like Jamie. On an undercover sting operation to uncover a prostitution ring, she'd been given the name Riley, and in a similar instance, Samantha, but she'd shortened it to Sam.
After 9/11, she'd used variations of her sister's name, Elisabeth, and that had lasted her a long time. Liz, Lizzie, Beth, Betsy, Lee, Betta, Isabelle, Bettina, Bess, Betty, Ellie, Liza...the possibilities had been endless.
In Andi Swann's unit, she was known as Target, because she always got hers.
The nicknames never really stuck though. Seaver called her Target only a quarter of the time, and usually only when joking.
Andi wasn't given to nicknames at all, and tried to discourage them, so Kate had never actively tried to spread it around.
When she went in to interview for the open BAU position, the thought of nicknames didn't even cross her mind.
A/N: More soon.