Markgraf was born in Bloomfield Hills, Michigan and attended Detroit Country Day School. At Detroit Country Day, she helped guide the soccer team to the state title in 1991, scoring 16 goals with 26 assists. She was also a volleyball player making the All-League team three times and was recruited at the Division III level. In soccer, she made the NSCAA All-American team one time and was chosen for the All-State team for all three seasons she played.
Markgraf attended the University of Notre Dame and graduated with a degree in Science-Business. She was a three-time NSCAA All-American, a three-time all Big East selection, the 1997 Big East defensive player of the year, and the defensive MVP of the NCAA's Final Four in 1995, the year in which her team won the NCAA women's soccer championship. She also co-captained the team her senior year. She also earned Dean's List for one semester.
Playing career
Club, 2001–2010
Markgraf was a member of the Boston Breakers in the WUSA league for three seasons, and she was named defender of the year for the Breakers in 2001. In 2005, she played professionally for KIF Örebro in the Swedish league alongside longtime USA teammate Kristine Lilly. She was scheduled to play with the Chicago Red Stars in the WUSA's successor, Women's Professional Soccer, in its inaugural 2009 season. However, the Red Stars announced in January 2009 that she would not play that season because she was expecting her second child. Ten months after giving birth to twins, she returned to the Red Stars in 2010, played nearly every minute of the season, and made the All-Star team. 2010 was her final professional season.
International, 1998–2010
In 1998, she made her international debut for the United States against Argentina, with Sobrero on the back of her jersey. She switched to Markgraf on the back of her jersey in 2004. She was the least experienced starter in the winning 1999 World Cup team and one of the youngest members of the team. The LA Times selected her to the All-World top 11 for her play at centerback that tournament. She started in the 2000 Olympic Games in Sydney, the 2004 Games in Athens, and was Co-Captain for the 2008 Games in Beijing. She won the silver medal in 2000, the gold in 2004, and the gold in 2008. She played 12 matches in 3 FIFA Women's World Cup, winning the title of World Champion in the 1999 World Cup hosted by the US. She was also a member of the teams that finished third in the 2003 World Cup hosted by the US and the 2007 World Cup hosted by China. In July 2010, after nearly a two-year break from international competition, she made her 200th career international appearance, in a friendly match against Sweden. She became the 10th woman in FIFA history to earn her 200th cap, a mark no male player has reached. She subsequently announced her retirement from the sport at the end of the WPS season, ending her professional career after playing 201 times for her country.
As of 2008, Markgraf lived with her husband and their children in the Milwaukee area. She has served on the Juvenile Law Center Board and is a member of the Notre Dame Monogram Club Board of Directors, as well as co-sponsored Milwaukee College Prep, a fundraiser benefiting under-served Milwaukee students. She has co-created life-skills programming for Milwaukee America-Scores and runs soccer clinics for various charities. In 2015, she graduated with a Masters in Kinesiology from the University of Wisconsin-Milwaukee with her research being selected to be presented at the Association for Applied Sport Psychology. She is completing her Masters in Counseling.