Mellinger trained at the
Central School of Speech and Drama. Her acting debut was as Miriam in the 1981 BBC television serialisation of
D.H. Lawrence's
Sons and Lovers. In the television serial
Small World (1988), based on the novel by
David Lodge, she played a central double role portraying the twins Angelica and Lily. Her stage appearances with the
Royal Shakespeare Company have included Lavinia in
Titus Andronicus and Perdita in ''
The Winter's Tale''. As well as acting, for the past twenty years she has taught communication and personal impact skills at her own training company. From 2017 to 2021 one of her clients was
Keir Starmer. In February 2025 it was reported that Starmer and Mellinger had a face to face coaching session at the Labour Party Headquarters in London on Christmas Eve 2020, in possible violation of
COVID lockdown restrictions. This issue was raised in
Prime Minister's Questions on 5 February 2025, with the
Conservative Party demanding a police investigation. In
The Guardian of March 2, 2025, Mellinger stated that she had broken no lock-down rules and had been a key part of Starmer's wider communications team for several years but claimed she had been a victim of misogyny in parts of the press and on social media. During Prime Minister's Questions on February 5, 2025, according to
Hansard, Starmer stated that on the day in question he was 'working on the expected Brexit deal with my team. We had to analyse the deal as it came in at speed and prepare and deliver a live statement at speed'. ==Personal life==