The result finished Panama atop Central American qualifying Group 2 with four points, one ahead of Nicaragua and three better than El Salvador.
Evans, who scored a pair in Wednesday's 3-1 win over Nicaragua, equalized in the 50th minute Sunday after Francisca Gonzalez gave El Salvador the lead three minutes before halftime.
Marta Cox, who the other goal against Nicaragua, gave Panama a 2-1 lead in the 55th, enough to assure her side of advancing to the CONCACAF finals when Norma Portillo tied the game for El Salvador in the 90th.
Panama joins Guatemala, which clinched its berth a week ago, and automatic North American qualifiers Canada, Mexico and the United States in the eight-team field next year.
Panama previously qualified in 2002, 2004 and 2006, winning only one of nine matches.