Since returning home to California, Professor Thielen has performed with the San Francisco Symphony, Opera and Ballet orchestras, the San Francisco Contemporary Music Players, Cabrillo Music Festival, and the Carmel Bach Festival. She is a frequent soloist with many choral groups throughout the San Francisco Bay Area.
Professor Thielen is the principal harpist of the Monterey Symphony and Opera San Jose, and second harpist in Symphony Silicon Valley, formerly the San Jose Symphony. She is also a member of the music faculty at Santa Clara University, and maintains an active private teaching studio of children and adults.
Professor Thielen's undergraduate studies were with Suzanne Balderston, at the University of California at Santa Barbara and the Music Academy of the West, followed by graduate studies with renowned harpist Lucile Lawrence, at Boston University and the Tanglewood Institute. She also received a Spanish government scholarship for a summer of studies with the celebrated Spanish harpist, Nicanor Zabaleta.
In 2007, with flute virtuoso Tadeu Coelho, Professor Thielen recorded Azules, a CD featuring music from Mexico and Brazil.