[2] She was singled out from the students by J. M. Barrie, who cast her in her first professional appearance, playing Tootles in Peter Pan at the Duke of York's Theatre in December, 1907.
[4] In October 1917, at Wyndham's Theatre, she made what The Times later considered to be her greatest success as Margaret, the "dream daughter" in J. M. Barrie's Dear Brutus.
[1] Celli was regarded as a versatile actress and she appeared in a wide range of roles, including Clara Eynsford-Hill in Pygmalion at the Aldwych (1920); Emmeline in a stage version of The BIue Lagoon (1920); and Septima in The Truth About Blayds (1921).
[5] The following year she appeared in another Milne play, The Great Broxoff at the St Martin's Theatre, with Edmund Gwenn, Mary Jerrold and Ian Hunter.
In 1926 she played Isabella Trench in Somerset Maugham's Caroline (1926), a role created by Marie Lohr, to whom Celli was quite favourably compared.