Willrich is from Grand Prairie, Texas.[1][2] She is the daughter of civil rights advocates.[1] Her father was a preacher.[1] Willrich volunteered for local political campaigns during her youth and intended to become a teacher.[1][2] Influenced by her activism, she decided to study law.[1] Willrich earned a B.A. (1974) and M.A. (1977) in political science, B.A. (1976) in history, and a teaching certificate at the University of Texas at Arlington.[1][3][2] She was its first female Black student body president.[3] Willrich attended Texas Tech University School of Law from 1977 to 1979 before transferring to Antioch School of Law where she completed a J.D. in 1982.[1][2]
From 1982 to 1987, Willrich worked for West Texas Community Legal Services in Fort Worth and practiced family law including divorce, custody, consumer action, and landlord and tenant disputes.[1][2] In June 1987, she became the managing attorney and director of domestic violence of Community Legal Services in Phoenix, Arizona.[4] From 1992 to 1994, Willrich was the assistant director of the administration of children, youth, and families division in the Arizona Department of Economic Security.[4][1] She supported legislation for technological improvements which provided computers to child protective services social workers.[4] From 1994 to 1995, she worked in private practice.[2]
For five years, Willrich was a volunteer pro tem judge before serving as a commissioner.[2] From 1995 to 1999, she was a commissioner in the juvenile and criminal division of the Arizona Superior Court in Maricopa County.[4] In this role, she was appointed by the Arizona Supreme Court to develop the draft of the re-drafted juvenile court rules.[4] Willrich served as a trial court judge in the juvenile, criminal, and family division from 1999 to 2005.[4] She was the first Black woman judge on the Arizona Superior Court.[4][3]
Willrich was an associate professor of law at the Phoenix School of Law.[4][5] In April 2007, she was awarded the Maricopa County NAACP Roy Wilkins Award for service.[3] In 2008, Willrich was elected to the board of Community Legal Services as its vice president.[5] Later that same year, she completed a Ph.D., summa cum laude, in criminal justice, criminology, and public safety at Capella University and was inducted into Alpha Phi Sigma.[6] On July 1, 2011, she was appointed as its associate dean of academic affairs, succeeding Shandrea Solomon.[4] On January 1, 2017, Willrich became the interim dean of the Arizona Summit Law School, succeeding Shirley Mays.[7]