Pacheco, 17, has made three appearances this season for Liverpool, who are fifth in the WSL One table.
Doncaster are currently bottom of the league, having failed to pick up a point from their opening four games.
"She's an extremely exciting and talented young player," Belles manager Emma Coates told the club website.
Doncaster Rovers Belles have signed Liverpool and England Under-19 defender Maz Pacheco on loan until the end of the Women's Super League season.