Nebraska's Morgan Marlborough and Boston College's Kristie Mewis gave the USA the early lead with their first goals of the tournament before Leroux, the former Canada youth international, finished off the scoring with a pair of goals late in the first half. She also scored twice in the 6-0 win over Jamaica.
The USA dominated T&T with a 19-2 edge in shots.
Canada (2-0 winner over Cuba) and Mexico (2-0 winner over Jamaica) also won their second games, though only Mexico clinched a berth in the semifinals. Costa Rica defeated host Guatemala, 3-0, in the other game.
Jan. 23 in Guatemala City
USA 4 Trin. & Tobago 0
USA - Marlborough (Quon) 5th minute
USA - K.Mewis 23rd
USA - Leroux 37th
USA - Leroux (Marlborough) 45th+1
USA -- Henninger, Quon, Dunn, Pressley, DiMartino (Eddy, 68), Short, S.Mewis, Nairn (Brooks, 60), K.Mewis, Marlborough, Leroux (Noyola, 57).
Trin. & Tobago -- Forbes, Borneo, Bateau, Mims, Matthias, Shade (Seaton, 69), Taylor, Lewis (St. Louis, 56), Kisoon (Swift, 78), McKenzie, King.
Referee: Arlene Troya Tejada (Panama).