Jeannette first trained as a singer and dancer at the Arts Educational School, after which she worked in theatre and cabaret for ten years in Britain and around the world. In her late twenties she took a degree in English at Queen Mary College, University of London and then retrained as a voice teacher at Central School of Speech and Drama. As a voice teacher she taught for many years at the Guildhall School of Music and Drama as well as working as a voice and dialect coach in theatre, film and television.

Besides the National Theatre, where she has worked since 1992, and as Head of Voice from 2007 to 2023, she has been resident voice coach at Shakespeare’s Globe, the Royal Shakespeare Company and Sydney Theatre Company, Australia.

Her other work in British theatre includes productions for The Royal Court, The Donmar, The Young Vic, Out of Joint, Shared Experience, Theatre de Complicite, Hampstead Theatre, English Touring Theatre, Sheffield Crucible Theatre, Birmingham Rep, Chichester Festival Theatre, Liverpool Playhouse, Salisbury Playhouse, Bristol Old Vic Theatre and many West End Theatres.

She also works as a voice and dialect coach in film and tv.