Will is a tomboy, but is also sensitive towards other people's feelings. She is known to have a fiery and unstable temper, just like her mom, but she has the personality of a great leader. Will has issues with trusting people because she is scared of being let down or rejected like, with her old friends in Fadden Hills. Her favorite subject is science, especially biology. Her hobby is swimming, and she's in Sheffield Institute's competitive team. She loves animals in general, but she is especially crazy about frogs. She collects anything that's frog related, except the amphibian itself. She's allergic to nettles. Will had a crush on Matt Olsen, which leads her to work at his grandfather's pet shop for a while, and, who later in the series becomes her boyfriend. He also encouraged her to adopt a pet dormouse that had been hurt by Uriah.
Will's full name shifts between "Wilhelmina" and "Wilma". Her birthday is given as January 19th in the comics, but is changed to the fall (possibly somewhere in November) in the animated series. In the comics, her star sign is Capricorn.
She is the leader of W.I.T.C.H. and holds the Heart of Kandrakar, a pink glowing jewel sphere that converts the five elements into pure energy, allowing the girls to transform and magnify their powers. Will has the power of Absolute Energy, also known as Quintessence (the power of life force manipulation), and can be seen in the form of lightning bolts. Her theme color is hot pink and her symbol is a pink, curved equal sign.