Peacock is known for her work on the use of microbial whole genome sequencing in diagnostic and public health microbiology, for research and policy work relating to antimicrobial resistance, and for her research on Burkholderia pseudomallei and Staphylococcus aureus including methicillin-resistant Staphylococcus aureus (MRSA).

[3] Following this, she did four years of postgraduate training in London, Brighton and Oxford, during which she obtained Membership of the Royal Colleges of Physicians (MRCP).

Peacock's work is particularly focused upon developing diagnostic and public health innovations from genome sequencing technologies.

During this time, she began collaboration with teams at the Wellcome Trust Sanger Institute[7] on whole genome sequencing of a range of pathogens.

She maintained a research programme in Thailand, working on the molecular epidemiology of Leptospira, infection mechanisms of Burkholderia pseudomallei and melioidosis.

[10] Peacock led a working group for the Department of Health's 100,000 Genomes Project and in 2017 contributed to the UK Chief Medical Officer's annual report on antimicrobial resistance.

In March 2020, Peacock convened a scientific group of national genomics experts to develop plans for a nationwide pandemic SARS-CoV-2 sequencing network.

Consortium members undertook research that revealed patterns of viral introductions and spread at local, national, and international levels.

These were released into global open access databases, prior to formal handover of sequencing responsibilities to public health agencies.

Peacock has a strong track record of mentoring within scientific and medical disciplines, driven by her own lived experience of leaving state-maintained education at 16 and taking a circuitous route to University.

[37] Peacock was appointed a Commander of the Order of the British Empire (CBE) in the 2015 New Year Honours for services to medical microbiology.

[38] In the same year, she was awarded membership of the European Molecular Biology Organization (EMBO) in 2015.,[1] and was named in the BioBeat "50 Movers and Shakers in Biobusiness" report.

[42] In 2022, Peacock was awarded an honorary doctorate by the Royal Veterinary College in recognition of her achievements and contributions to the One Health agenda.