Katie is most notable for being Sadie's best friend. They do everything together, even wear the same outfits which Katie sews herself. Like Sadie, Katie is a sensitive, cheerful, and kind-hearted girl. She's boy-crazy and when she has grown attracted to someone, she (and Sadie) will fawn over him endlessly. Katie can be considered as the more passionate one between her and her best friend. Her biography states that she "thinks with her heart", in contrast to Sadie who "thinks with her head". This may imply that Sadie could be more logical, whereas Katie has stronger relationships than Sadie. She is shown to have a bad sense of direction, a flaw which produces tragic results. Sadie's label of "The Sweet Girl's Friend" may imply that Katie is more independent and capable of making decisions on her own. However, given her thinking habits, they don't always turn out to be wise.