Born in Australia, Adey trained as a dancer and actor as well as a singer. She worked in radio broadcasting, choral music and theatre and was in the original Australian casts of Cats and Les Miserables before she ran away. She has worked in the UK since 1988 for companies including English Touring Opera, Opera North, Welsh National Opera and D'Oyly Carte in classical repertoire from mainstream to contemporary.

She has created soprano roles in new operas by Julian Grant, John Woolrich, Graham Coatman, Ian McQueen, Derek Clark, Wim Henderickx, Russell Keable, and Stephen McNeff. For other companies, she created the role of Rosa in Tête à Tête's UK tour of Family Matters and in 2005 she performed, to much acclaim, a new realisation by Waut Koeken of Peter Maxwell Davies' The Medium for Musiektheater Transparant in Antwerp and at the Teatro Colon in Buenos Aires.

For the notorious Richard Thomas, she brought to life the pole dancer Shawntel in Jerry Springer - The Opera at BAC and Mags in Stand Up at the Schauspielhaus in Hannover. She has also appeared with Thomas in his cabarets Kombat Opera Klubneit and The Lonely Death of Weihnachtsmann and Tête à Tête's Afters with members of Ballet Rambert. In 2006 she completed filming his five new pieces for TV. Kombat Opera Presents was televised in February and March 2007 on BBC2. In 2007 and 2008 she helped devise and played Maria 1 in Cattle Call with Thomas and Javier de Frutos at Phoenix Dance Theatre.

She has made concert and recital appearances at Wigmore Hall, St John's Smith Square, Purcell Room, Holywell Music Room, Snape Maltings, Glasgow Royal Concert Hall, York Early Music Centre, Royal Albert Hall, Birmingham Symphony Hall, Bridgewater Hall and the Hackney Community Farm.

Adey’s passion is devising and developing new work with contemporary artists in all media. In 2003 Battersea Arts Centre, commissioned Stephen McNeff to write Names of the Dead for her and the Duke String Quartet. In 2004 they also premiered McNeff's Cabaret Songs. She has worked several residencies as a singer for the Jerwood Opera Writing Course at Snape Maltings.

She also sings with the jazz/world/contemporary fusion group The Shout. Orlando Gough composes for and artistically directs the 16 diverse singers who are drawn from vocal traditions and styles all around the world.

Adey conducts and directs her own group, the all-female vocal ensemble The Curate's Egg and she sits on the board of the Society for the Promotion of New Music. Her book Suddenly He Thinks He's A Sunbeam was published in 2000 and she also writes lyrics for any composers who smile at her winningly or get her drunk enough.

She can play the Hawaiian guitar on her nose.