yes. if you train your girls with the scrog screen dropped when they get 12 inches tall (approx. 4 weeks In veg) and leave that screen down and weave your branches nice and long. 2 plants will completely fill your 4 by 4 except for 2 small corner portions of the screen. You should place one plant in the back left corner and the other in the front right. Stretch your branches to fill the screen diagonally so that they both get the same amount of room.
I hope your running indicas.. cuz sativas.. well ....only one can fit. lol