Mary, Practically Perfect

When Mary, Practically Perfect enters the battlefield, target an opponent.
Creatures you control have base power and
toughness 3/3.
Creatures you control get +2/+0
for each other creature you control with base
power and toughness 3/3 you control, and an additional +0/+2 for each creature with base
power and toughness 1/1 that target opponent controls.