In January 2013, Mewis was called to the national training camp by head coach Tom Sermanni in preparation for a friendly match against Scotland.[31] She made her debut for the senior team on February 9, 2013 against Scotland and was placed on the roster for 2013 Algarve Cup.[32] Mewis scored the game-opening goal in the third minute of a friendly match against South Korea on June 15, 2013, near her hometown in Massachusetts.[33]