In 2004, at the age of eleven, Cori made her debut on the national women's team at the 36th Chess Olympiad. She played on the reserve board and scored 5 points out of 7 (four wins, two draws, one loss). She finished tied for first with Martha Fierro in the Women's American Continental Championship in September 2009, placing second on tiebreak. In November 2009, Cori tied for first place at the World U-20 Girls Championship, taking the silver medal on tiebreaks. Later that month, she won the girls under 16 section of the World Youth Chess Championship in Antalya, Turkey, winning nine of her first ten games, and clinched the title with a round to spare. In November 2010, Cori finished second in the girls under 18 division of the World Youth Championships in Porto Carras, Greece. Cori won the American Continental Women's Championship for the first time in June 2011. In August 2011, she won the World U-20 Girls Championship in Chennai, India and this achievement earned her the qualification for the Women's World Chess Championship 2012.