[5] Fagan grew up in Sydney, and received a business degree in Australia, before studying at London's Guildhall School of Music and Drama, and joining The Royal Opera's Jette Parker Young Artists Programme.
Toward the end of her studies, she was a member of the Glyndebourne Festival Choir, where she sang in Tchaikovsky's Eugene Onegin, and Mozart's Don Giovanni, and performed the role of Annina in La Traviata.
She also played the role of Lia in Debussy's L'enfant prodigue at the Barbican Centre, the Blue Fairy in Jonathan Dove's The Adventures of Pinocchio, participated in the Banff Summer Arts Festival in Canada as Mrs. Coyle in Britten's opera Owen Wingrave, sang Frasquita in Bizet's Carmen, and took part in the Australian premiere of Jake Heggie's opera Dead Man Walking.
During this time, she performed roles such as Oscar in Verdi's Un ballo in maschera, Giulia in Rossini's La scala di seta, Gianetta in Donizetti's L'elisir d'amore, the Girl in Weill's Rise and Fall of the City of Mahagonny, Papagena in Mozart's The Magic Flute, Lila in David Bruce's The Firework-Maker's Daughter, the Lover in Puccini's Il tabarro, Sister Genovieffa in Puccini's Suor Angelica, and Ines in Verdi's Il trovatore.
She also performed Donna Elvira in Mozart's Don Giovanni with the NHK Symphony Orchestra under Paavo Järvi, sang Agnès in George Benjamin's Written on Skin with the Melos Sinfonia under Oliver Zeffman in London and St. Petersburg, and returned to Opera Holland Park in London for her debut as Verdi's heroine Violetta in La Traviata.