The Were Chronicles by Alma Alexander Books in Order

Jazz Marsh belongs to a family of Random Were, whose changing forms depend on the creatures they see before transforming. Discovering her dead sister's diaries exposes family secrets, while her brother's troubled behavior challenges everything she understands about their kind.

Mal Marsh has waited longer than anyone in his generation for his first transformation. Burdened by guilt over his sister's death, he chooses to become a Lycan, hoping to pursue revenge while discovering complications hidden within his family's history.

Saladin van Schalkwyk knows he was created as a genetic chimera but cannot uncover the purpose behind his existence. When his friend Mal infiltrates the Lycans to investigate, their search exposes secrets that challenge Saladin's understanding of himself.