I monitor the curvature of the nose/mouth area and skin textures(im good at mature firebellies). The wife looks for the pads on the feet shes good at that part where im still learning. redeyetreefrog.org also suggests the female barks once then shakes to notify the male of her location. Lilly also sleeps close to or over the pond. Herman wanders where he pleases.

Perhaps time shall tell as to Lillys true sex. Currently all 13 of my frogs are having a growth spurt. Its strange how all their growth, no matter origin kind of goes together. Even the green anoles and long tails are in "the season" here but thats a discussion for elsewhere