A 2008 graduate of College Park High School in Pleasant Hill, California, competed for the water polo teams all four years and for three years on the swim team, she also played soccer as a preparation. Captained the water polo team in 2007 and 2008, helped lead team to DFAL title as a senior, was named a NISCA All-American as a senior and was named Team MVP in 2007. Member of the U.S. Youth National Team in 2006 which won the gold medal at the Pan-American Junior Games, was the leading scorer in that tournament with 20 goals. Seidemann was a member of the youth national team that went undefeated in Sydney, Australia over the summer of 2007 and also part of the team that competed in the 2008 Global Championships. She earned All-America honors at the U.S. Water Polo 20/U Nationals.
College
Seidemann joined the Stanford University women's water polo team in 2009. As a freshman, she led the team with 59 goals, scoring at least four goals in a game on five occasions. She led Stanford in scoring again the following year and was also named to the ACWPC All-America First Team. In 2011, Seidemann had her third-straight 50-goal season, finishing second on Stanford with 51. She scored a goal in the NCAA Championship title game, which Stanford won. Seidemann took a leave of absence from Stanford in 2012 so she could train with the U.S. national water polo team.
International
Seidemann started playing for the U.S. national team in 2010. She scored three goals in that year's FINA World League Super Final and two goals in the FINA World Cup, helping the U.S. win both events. The following year, the U.S. won the FINA World League Super Final again, with Seidemann scoring twice. She scored 11 goals in the Pan American Games, ranking third on the team, and the U.S. won the gold medal and qualified for the 2012 Summer Olympics. The U.S. went on to win gold at the Olympics as well. She was also part of the US team that won gold at the 2016 Summer Olympics.
Personal
Graduated Stanford in 2013 with a degree in psychology. She has one older sister, Lauren, and a younger sister, Natalie. Lauren is the women's water polo head coach at College Park High School in Pleasant Hill, California, and Natalie is currently a center on the UC Irvine women's water polo team.
