Conversation so far:
Who was Martina Hingis's partner in a doubles match?
Martina Hingis' doubles partner was Anna Kournikova.
Did Martina Hingis and Anna Kournikova win?
1999 saw Hingis win her third successive Australian Open singles crown as well as the doubles title (with Anna Kournikova).
What games did Martina Hingis play in the US?
In 1997 Martina Hingis defeated another up-and-coming player, Venus Williams, in the final of the US Open.
Did Martina Hingis win any titles?
Martina Hingis has won 43 WTA and 2 ITF titles.
Who did Martina Hingis beat in order to win the title?

Question: what is a notable fact regarding the US doubles?
Self-contained rewrite: what is a notable fact about Martina Hingis regarding the US doubles?