Viola is J.T.'s mom and Emelina's mom-in-law. In this female-centric novel, she's a way bigger character than J.T. Back when Codi and Hallie were little, they used to hang out at Viola's house and play with J.T. all the time. They'd to go with the Domingos family to celebrate the Day of the Dead, and Viola was still nice to the Noline girls, even though these little Anglo kids were always messing everything up.
Viola herself feels strongly about tradition: she wants her grandkids to speak Spanish, and she's one of the leaders among the Stitch and Bitch craft nobility. As Codi learns more and more about her past, Viola becomes more central to the novel. She's one of the people who knows the most about Codi and Doc's history, and in the end, it's Viola who accompanies Codi up to the place where her mother died. She kind of adopts Codi as an adult, and although she's never particularly sweet, she's a rock-solid person. She always comes through for Codi, and for her town.