Though Lutheran, after receiving her basic education from a school run by Catholic nuns, Dreyer traveled to England in 1914 as a nanny to a Swiss family who had settled abroad.
[2] Dreyer entered nurse training in 1918 at Guy's Hospital of London and earned her state registration certificate in 1922.
[2] During her tenure, Dreyer managed the often difficult process of improving the status and professionalism of the nursing profession without becoming aligned with the politics of her employers.
[8][9] At the outbreak of World War II in 1940, Dreyer was promoted to principal matron in charge [1] as the LCC hospital and district medical services were mobilised to receive civilians wounded in air raids.
This appointment attracted xenophobic attention of Ethel Bedford Fenwick who denounced Dreyer as being of 'German blood'; forcing Dreyer to make public statements of denial and gaining the public support of the Royal College of Nursing (RCN) and the leader of the LCC, Charles Latham.
[1][3] During the war, with the increased need for staff, Dreyer had to make difficult decisions as to whether nurse training or serving the public was the imperative.
At a public event at County Hall to mark the commencement of the NHS, Herbert Morrison, then leader of the LCC, singled Dreyer out for special tribute.
The occasion was marked by a presentation of a cheque, said to be one of the largest in the history of the LCC, by Sir Allen Daley, the County Medical Officer of Health.