In 1888 she became a private nurse for Red Cross and in 1893 one of her patients was Johanne Petersen.

Johanne Petersen grew fond of Fiedler, who was employed as a full time nurse at the Cripple Home in 1894.

Although her main assignments were at the hospital beds, Fiedler began constructing bandages and prosthetics on her own.

When she had finished a prototype, she had the home's patients construct the prosthetics as work therapy.

Fiedler invented a number of prosthetics, adapted to the individual, that allowed patients to handle many things themselves, which they would have needed a nurse for otherwise.

[2] After leaving her work in 1921 Fiedler moved to Lynge near Sorø, where her parents had lived.