Diana earned her Juris Doctor from Washburn University in 1991. She soon joined the legal department of Kansas Power and Light Company, now Westar Energy, where for seven successful years she provided legal support to the company's gas pipeline and electric utility businesses, and its deregulation, merger and acquisition efforts. Ms. Edmiston then served for four years as the Senior Assistant General Counsel for the Kansas Corporation Commission, where she supervised the Oil and Gas Conservation Division legal staff. Ms. Edmiston then joined Murfin Drilling Company, Inc. as its General Counsel, where she provided land and legal support for the company's oil and gas operations. In 2006, Ms. Edmiston established Edmiston Law Office, LLC, where she represented a variety of clients on oil, gas and energy matters.

Ms. Edmiston is active in a number of professional organizations including the Kansas Bar Association's Oil, Gas and Mineral Section, the Wichita Association of Petroleum Landmen, and the Legal Affairs Committee of the Interstate Oil and Gas Compact Commission. She actively volunteers her time and resources to Big Brothers Big Sisters of Sedgwick County, where she serves as a Big Sister, as well as a member of the Big League. She also dedicates several hours each week to the Leukemia and Lymphoma Society's Team in Training program, where she mentors beginning marathon runners.

Ms. Edmiston serves on the Board of Trustees of the Kansas Oil Museum and on the Board of Directors of the Kansas Independent Oil and Gas Association.