[4] In the same year, she married John Norman Hardwich, who at the time, was working as an engineer in the High Voltage Research Laboratory at Metropolitan‑Vickers.

He was an associate and supporter of the Women's Engineering Society, and he shared the burden of running the home to allow Isabel to continue working at Metropolitan‑Vickers.

[3][2] After completion of her apprenticeship, Hardwich worked in the Research Department at Metropolitan‑Vickers, becoming one of the original members of the electron microscope team.

After a year and a half of working on this project she shifted her focus and began building a photometric laboratory, however this was badly damaged in a fire.

[5] By 1959, Hardwich was working with beryllium to find the optimum method of refining, melting, and welding it, for use in cans holding enriched uranium inside nuclear reactors.

[10] She joined in 1941 and helped to set up its Manchester branch the year after, alongside her great friend motor engineer Elsie Eleanor Verity, and Dorothy Smith, a colleague at Metropolitan‑Vickers.

As chairman, she gave the first talk organised by the Manchester branch in that year, an address entitled "Lighten Our Darkness", that introduced the theory of relativity.