A Fistful Of Sky by Nina Kiriki Hoffman.
In modern-day Southern California, Gyp has a witch mother and a non-supernatural father. Children through her mother’s line usually “transition” during adolescence to manifest exciting magical powers. A few “mundane” children never get magical powers, and a rare few manifest the “dark power” of cursing, which must be exercised or it will destroy the child.
Gyp reaches her twentieth year in her squabbling, flamboyant family, believing she is “normal” like her dad. Then she develops the power of cursing. She must work magic, or have it consume her, and it always comes out dark and twisted. How can she manage her powers without hurting anyone?
This is a good premise and there are some powerful flashes of darkness through the novel: some of Gyp’s curses, Gyp’s sociopath mother, Gyp’s older relatives’ harrowing past with their sociopath families. There’s also an appealing realism to Gyp interacting with her siblings, job, boyfriend. A good read. A Fistful of Sky can be found on Amazon through this link:.