She has worked with many directors and conductors, including Sir John Eliot Gardiner, Lars Ulrik Mortensen, Laurence Cummings, William Christie, Roy Goodman and Stephen Layton.
[4] She appeared on numerous recordings, including Pinchgut Opera's Fairy Queen[1] and Dardanus, The Wonders of the World with Echo du Danube, Mozart's Requiem with the Leipzig Kammerorchester and Gewandhaus Kammerchor.
[1] She performed in performances of Purcell's The Fairy Queen[1] with Glyndebourne Festival Opera, Israel in Egypt with Maulbronn Kammerchor and Monteverdi's 6th Book of Madrigals with Les Arts Florissants, and in the Australian premiere of Bach's reconstructed Markuspassion in the Sydney Opera House under Arvo Volmer.
She is married to Richard Bannan, a lay clerk of St George’s Chapel Windsor.
On 17 April 2021, Allan was one of a choir of four singers (three of whom were Lay Clerks of St George's Chapel Choir) during the funeral service of Prince Philip, Duke of Edinburgh, at St George's Chapel, Windsor Castle.