Yonina began her legal career as a human rights lawyer, seeking accountability from state officials for prolonged arbitrary detention. She then practiced civil rights and employment law at Sanford Heisler Sharp, LLP, and union-side labor law at McCracken, Stemerman & Holsberry, LLP, both in San Francisco. Upon leaving practice, Yonina taught legal writing at Stanford Law School and served as a volunteer and contract attorney for Bay Area Legal Aid. Yonina received her J.D. from Harvard Law School and clerked for the Honorable Roslyn O. Silver of the United States District Court for the District of Arizona. She is also a graduate of Johns Hopkins University.