Lynn was part of the founding company of the National Theatre of Great Britain in 1963, now the Royal National Theatre.  She appeared in productions of "Hamlet," "Much Ado About Nothing," "Mother Courage," "Andorra," and "Love for Love," among others.  Her directors included Laurence Olivier, Franco Zeffirelli, Lindsay Anderson, and Noel Coward.  Among the actors she performed with were  Olivier, Peter O'Toole, Maggie Smith, Robert Stephens, Tom Courtenay, and her father, Michael Redgrave.