What nickname did Virginia give to her artificial leg as noted in the biography, A Woman of No Importance?

"Cuthbert" is the nickname that Virginia gave to her artificial leg. She sometimes referred to him in her coded transmissions to her superiors in England and in the United States. Occasionally, her references confused people who did not know who "Cuthbert" was, and who commented on him as an individual. The narrative contains several references to how Virginia refused to let herself be limited, or held back, by Cuthbert's presence in her life.