Who is Aunt Jezie from Little Altars Everywhere and what is their importance?

Aunt Jezie is Viviane's younger sister. She is attending college at Ole Miss, the University of Mississippi. When she returns home, Jezie and Charlene Parks become good friends. At first, Sidda is excited that her favorite aunt and favorite teacher have forged a friendship. Unfortunately, that excitement quickly ends when Sidda begins to feel left out.