The Annotated Watchmen describes Jupiter's character as:
SILK SPECTRE I (1921-?): Sally Jupiter, nee Juspeczyk. She changed her name to hide her Polish heritage. A former waitress and burlesque dancer, she became a crimefighter in early 1939 on the advice of her agent, Laurence Shexnayder.
She was a member of the Minutemen; the Comedian was expelled from the group after attempting to rape her. She left the team and retired in 1947 to marry Shexnayder.