After earning the B.S. from KU Beier spent two years working for the Kansas City Times. Upon obtaining her J.D. she served as a clerk to then Judge James Kenneth Logan of the U.S. Court of Appeals for the Tenth Circuit.
She start her career as a Staff Attorney in Litigation and Legislation Practice at the National Women's Law Center through the Women's Rights and Public Policy fellowship program of the Georgetown University Law Center. After finishing the fellowship she entered private practice focusing on white collar criminal defense for Arent, Fox, Kintner, Plotkin & Kahn in Washington, D.C. from 1987 to 1988. She came back to Kansas in 1988 and practiced litigation concentrating on commercial disputes and health care law at Foulston & Siefkin L.L.P. in Wichita eventually becomming a partner at the firm.
In 2000 Beier was appointed to the Kansas Court of Appeals where she served until being named to the Kansas Supreme Court to replace retiring Justice Bob Abbott in 2003. She will face her next retention vote in 2010. In 2004 she retained her seat with 702,423 (76.4%) for her and 215,948 (23.5%) opposed.
Justice Beier is a member of the American Bar Association, American Judicature Society, American Bar Foundation, National Association of Women Judges, Kansas Bar Association, D.C. Bar, Kansas Women Attorneys Association, the Wichita and Topeka Bar Associations, and the Institute of Judicial Administration at New York University School of Law.