Peters made her WNBA debut on May 20, 2012, scoring 3 points and grabbing 4 rebounds in a win over the Phoenix Mercury.
Peters quickly became the first power forward off the bench, and led the team in field goal percentage through sixteen games. In July, Peters broke a finger on her left hand, forcing her to miss three games.
Peters would remain the primary backup in 2013, leading the Lynx in blocked shots. She played a key role in the Lynx's second WNBA championship, serving as a reliable defensive presence.
Peters played on the team presenting the USA at the 2011 World University Games held in Shenzhen, China. The team, coached by Bill Fennelly, won all six games to earn the gold medal. Peters averaged 10.0 points and 5.3 rebounds per game.