Katherine O-Dell is one of the Fox's many neighbors. She is usually called Katie. She is 9 months old at the beginning, but becomes a toddler by the last time. Paige often babysits for her, and Katie does not make it easy.
In Katie's debut, after her mother Margaret gives Paige babysitting instructions, Katie cries when her mother leaves, even as Paige tells her to say goodbye to her. Then when Paige tries to assure her that her mother will be back, and they would have fun in the meantime, Katie throws a block at Paige's nose, to Katie's own amusement. She refuses even a spoonful of her mushed peas, proving that her mother was right about her being a smart girl. Somehow, Katie cries later, but Paige doesn't get it, as she just fed her, figures she wants her to read to her, and smells what she assumes to be "dog doo." Then Katie keeps saying, "Pag!", which is her way of saying "Paige." At first, Paige decides she'll never forget it, but decides it's not that she won't try to. At bedtime, Paige chases after her, and as she brings her to bed, she lectures her on bedtimes existing for a reason, and not to make any "ifs," "ands," or "buts" when she is supposed to be in bed when her mother wants her there. She eventually cries herself to sleep.
Paige once unintentionally taught her two curse words by watching the Jersey Spaniel Show, a show she was no more supposed to watch than Katie was. Another time, Katie is excited enough to wear her fancy new dress while a sleepy Paige comes over, but while Paige sleeps on the job, Katie plays with her mother's scissors, chopping up her new dress. So Paige tries to convince her to come up with a story like Paige was playing Mozart or flashing cards, but it ends up being "flashing Mozart." Therefore, Paige has to buy a new kiddie dress and spend hours apologizing to Mrs. O'Dell for sleeping on the job.
Another time, Paige gave Katie some chocolate cake against her own will, which makes Katie literally bounce off the walls, causing Paige to say she "created a gas molecule."
Paige once unintentionally gave her M rated video games.
Another time, starting from when Paige arrives to baby-sit, Katie keeps yelling, "Blue's Clues!" over and over for four of the five hours straight, but she doesn't give in because Mrs. O'Dell had said she could not watch any television or videos while Paige was there as a punishment for misbehaving more than usual that same morning. Eventually, she mentions, "Dawson's Creek?" when it is clear that no number of times she says, "Blue's Clues" was going to get Paige to let her watch television.
In two Sunday strips, revealing that she is a strawberry blonde, there are incidents about food. In one, when Paige offers her a spoonful of mashed carrots, peas, bananas, broccoli, or plums and pears, she blows raspberries of them into her face, and then says, "Mo carrots!" prompting Paige to wear a visor. In another, when Paige tells her to eat a certain vegetable, she says, "No!" and throws that vegetable at her in the face.