Has the frog had a fecal float done? Maybe she has gastrointestinal parasites. Or maybe she just has food preferences, though most frogs don't.

Also, 81 F isn't bad. These frogs range over most of Australia and New Guinea and can be found in many kinds of eco-systems, from tropical rainforest, to blistering deserts, to temperate forests of Southeastern Australia. Mine seem to do fine in the mid to upper seventies.