Marianne trained at the Bristol Old Vic Theatre School. 

Previous theatre credits include: King Lear (Shakespeare’s Globe), hang (Crucible Theatre), A Monster Calls (Bristol Old Vic), Rosencrantz and Guildenstern Are Dead (The Old Vic), The Argument (Hampstead Theatre), The Boy in the Striped Pyjamas (Chichester Festival Theatre), Sons without Fathers, Uncle Vanya (Arcola Theatre / The Belgrade Theatre), You can still make a Killing (Southwark Playhouse), The Real Thing, The Changeling (ETT), Hamlet (The Factory), Design for Living (Salisbury Playhouse), Persuasion (Salisbury Playhouse), The Years Between (The Royal & Derngate), The Girl in the Yellow Dress (Market Theatre Johannesburg/Live Theatre Newcastle), An Inspector Calls (Novello Theatre / Wyndhams Theatre), Mad Forest (BAC), Mimi and the Stalker (Theatre 503), Troilus and Cressida (Cheek by Jowl), Hamlet (The Factory), Sweethearts (The Finborough Theatre), Relatively Speaking (English Playhouse Theatre), How many miles to Basra (West Yorkshire Playhouse), The Cherry Orchard (Southwark Playhouse), Present Laughter (Theatre Royal Bath), Intermission (True/False), Finally the Girl (Old Red Lion), The Venetian Twins, The Gentleman from Olmedo (The Watermill Theatre), and We Happy Few (Malvern Theatre). 

Television credits include: The Midwich Cuckoos (Sky), Endeavour, Foyle’s War, Grantchester (ITV), A Very English Scandal, The Living and the Dead, The Musketeers, The Crimson Field, Doctors, The Impressionists, WPC56 (BBC), Life in Squares (Ecosse Films for BBC), and Obsession (October Films). 

Film credits include: Finding Your Feet (StudioCanal), Absolutely Anything (Bill and Ben Productions), Silent Girl (Ascension Productions), Titus (Dakus Films), and 500 Miles North.