Laurence Olivier flew to Boston to confirm the opinion of American reviewers and chose Donlan to star in his production of the play to be staged in London's West End.

[4] After her run in Peter Pan ended, Donlan remained in the United Kingdom and began accepting film work.

After Traveller's Joy (1949), Donlan worked for the director Val Guest as the female lead in several films including Miss Pilgrim's Progress (1949) with Michael Rennie, The Body Said No!

(1950), with Michael Rennie; Mister Drake's Duck (1951), with Douglas Fairbanks Jr., and Penny Princess (1952) in the title role co-starring with Dirk Bogarde.

Her autobiography, Shake the Stars Down, was published in 1976 (known as Third Time Lucky in the USA), which concentrates on her childhood years growing up in the household of her actor father James Donlan in the Hollywood of the 1930s.