Melissa Williams
The nurse at Ravencrest High School. Freshly out of college, Melissa was hired at the school almost over night. The 2011 school year was her first year working there.
Though still a young witch, she has a lot of pull in the community. In Season of the Witch, she becomes a mentor figure to Kelly and eventually her teacher. A few months before that---in Song of the Sea---she's one of the few who knows about Ashley Martin's Nereid nature.
In I Bump Back, it was Melissa who ascertained what kind of curse Mike might have been under and removed the "Slut Galmor" from him, allowing him to lead a normal life.
Back in highschool, Melissa was Mary's babysitter.
Melissa's Familiar is named Phoenix.