Green and Golden Bell Frogs - and cannibalistic tenancies.

[Elsha]

You may have to do some waiting.
If the smaller frog is a female it will take around twice as long to grow to the other frogs size than if it were a male.
What exactly is the size difference? I can't really tell from the photos.

We're not sure what the sexes are, too young to tell. The smaller one is about 1.5cm smaller in length.

[Whistly]

They should be starting to hibernate now so they won't grow for 3 months. So you could just put hiding spots in the temporary tank and leave it in there, that way you have three months to sort something out. I'd reccomened making a new setup for the smaller one while it grows. When it's big enough they can go in together and you have a spare tank, which you could put hmmmmmm maybe some Brown Tree frogs into