Joslyn has been acting in middle and high school theatre since she was twelve years old, eventually taking on the role of assistant director and choreographer of the middle school drama club. In high school, she played Charlotte in Charlotte's Web, Baroness Elsa Schraeder in The Sound of Music, Rosie Alvarez in Bye Bye Birdie, and Marian in The Music Man. Since coming to UK, she has played Lady Sneerwell in Sheridan's School for Scandal.