Willa is a fifth grader in the Upside-Down Magic class with Ms. Starr. She is described as a kind, elfin girl. Willa is an upside-down Flare; she makes it rain indoors. Because of this power, Willa often causes problems. Willa is the focus of Upside-Down Magic #5, Weather or Not.
Willa is described as a willowy, blond, elfin girl with braces, all elbows and knees.
Willa was previously labeled as an upside-down Flare who makes indoor rain. She is now known to have water magic and calls herself a Fluid. Willa's power can be triggered consciously or by her emotions. She has trouble controlling her abilities, though calming down helps her stop the rain. Willa makes small rainclouds that can cover an entire room or a section small enough to rain on just one person, which often happens to be Bax. She works with Elliott, who is also an upside-down Flare. She is being tutored by Ms. Cruciferous.
Willa is a relatively quiet girl, but she is not shy. She is insecure about her own power, thanks to the amount of damage it often does, and panics in stressful situations. She also cries when upset, which happens easily. The Sparkies can do it with a few words. She is best friends with Marigold. She tends to exhibit signs of ADHD, such as forgetfulness, very strong emotion, etc.
Willa lives with her parents, Chase and Gaia, both Fluxers, and her older sister, Edith. She was in chorus in ordinary school.
- Willa is the only member of the UDM class known to have braces.
- She is the sixth member of the UDM class, along with Bax , Elliott , Marigold , Pepper, and Andres, to have practiced a musical instrument, in her case her voice.
- Willa causes more magical accidents that most of the UDM students.
- The name "Willa", the feminine form of William, means "resolute protector".