[1][2] Her parents, who were originally from Liverpool, run a project management and engineering business in Harrogate.

She read German and French (Modern and Medieval Languages) at the all-female New Hall, Cambridge, now Murray Edwards College.

[7][8] In that position, she spearheaded and oversaw the £2.5 billion rollout of fibre broadband (BT Infinity service) to two thirds of the UK.

[6] In March 2017, BT received the biggest Ofcom fine ever of £42 million due to inappropriate use of the Deemed Consent to delay Ethernet provision to other providers, which started and continued in January 2013 through to December 2014 while she was CEO.

[13] As of May 2018, Garfield's role at Severn Trent made her the youngest female CEO of a FTSE 100 company.

[14][15] She was appointed Commander of the Order of the British Empire (CBE) in the 2020 Birthday Honours for services to the water industry, while at the same time the aggregate annual spill durations to rivers and streams from Severn Trent's sewer overflows totalled 64 years.