Conversation so far:
What happened at the early stage of Billie Jean King's career?
Billie Jean King's triumph at the French Open in 1972 made her only the fifth woman in tennis history to win the singles titles at all four Grand Slam events.
How did Billie Jean King's career end?
Billie Jean King retired from competitive play in doubles in March 1990.
Did Billie Jean King win any award or recognition?
Billie Jean King was inducted into the International Tennis Hall of Fame in 1987. The Fed Cup Award of Excellence was bestowed on her in 2010.

Question: Which of her awards is the most notable?
Self-contained rewrite: Which of Billie Jean King's awards is the most notable?