A member of the SS-Aufseherin, or overseer, Beilhardt was also a nurse affiliated with the German Red Cross during the last year of World War II.

According to a Polish historian, the case of Beilhardt is the only known instance of an SS guard outright refusing to serve in Stutthof after receiving training.

[4][5] Due to her family's difficult financial situation, especially with the end of World War I, Beilhardt, who had just graduated from elementary school, went to East Prussia, where she found a job in agriculture.

[4] After moving to Danzig, Beilhardt completed her education at a two-year vocational school and worked as a housekeeper in an apartment with the factory director, Willi Lippert.

[4] During the war, Beilhardt underwent additional medical training and joined the NSV, the Nazi Party's welfare program.

"[4][5] Due to her voluntary resignation and lack of direct involvement in the abuse or murder of any prisoners, Beilhardt was not sentenced for crimes against humanity.

Instead, she received a five-year prison sentence for her membership in the Nazi Party and the SS, making her the only SS-Aufseherin from Stutthof to be convicted by a Polish court and avoid execution.