Status Updates From Mary Underwater

I feel for Kathleen, she sort of exists to be someone Mary can look down on. I wonder, is she GOOD at drawing the unicorns? Is she illustrating specific scenarios with them, an ongoing story perchance? Is she talking to the unicorns when she talks to the page(and if so, how?) or is she just someone who mutters to herself while she works? Is she a nice person? How does she do in school? What is HER home life like?

Kathleen mentioned on this page again. I checked the digital version, and it is apparently the last time she shows up in this book.