Welcome to the forum Emma. A frog sounds like a fantastic present. I don't know if you're stuck on a Whites Tree frog but I would recommend a couple of fire belly toads instead. Here's why:
1. They are diurnal so they will be awake when your child is awake. Sometimes nocturnal frogs don't wake up until late in the evening.
2. They are very hardy and don't stress as easily as most other frogs.
3. They are very active and will entertain small children. Frogs that don't move all day tend to get boring to small kids.
Just some thoughts.