Red-Eyed Leaf Frog Advice Please

[Tony]

she doesn't chirp as much anymore

Are you sure "she" is a female? Female red eyed tree frogs do not call so the lack of noise would be perfectly normal, if both frogs used to call then you had two males.

I prefer to keep my red eyes in groups. A single frog will live on its own just fine but you will miss out on some very interesting behaviors when they don't have others of their species to interact with,