Pettersen served as an apprentice to Frank Lloyd Wright as part of the Taliesin Fellowship from 1941 to 1943. Over the years, she collected material, such as newspaper and magazine clippings, newsletters (Frank Lloyd Wright Building Conservancy and FLLW Update), documenting Frank Lloyd Wright, his buildings, and his legacy. She also collected material, such as correspondence, publications, and clippings relating to Taliesin Fellows.

The General subseries focuses on the daily operations of the practices with an emphasis on financial matters. Materials present include: invoices, architectural fees, budget correspondence, purchase order books (1972-2000) and appointment books (1993-1998).