Injured White's "Dumpy" Tree Frog!

[John]

Do I try to get this stuff in her mouth?

Let's be sure of what the problem is before we treat her - I don't see the problem area in that photo - can you point it out or describe it please? The white spot at the bottom looks like normal colouration to me.

Can I mix it and put it on her skin?

Without knowing what it is I would say that is dangerous. Trusting pet shop employees is a dangerous game when it comes to amphibians - they are not the same as reptiles. Does the container have a list of active ingredients?

Or should I put it in her water to be absorbed that way?

It's very hard to give the right dosage to the frog if you do that.

Is there anything else I can do to ensure she's okay?

Is she eating fine? A good appetite? Is she active? Does she seem otherwise healthy?