Female whites tree frog reacting to a male croaking

[Louis Charles Bruckner]

Brownie the female of the trio I own has displayed a odd thing.

I know for a fact that Bubba and Buster are males due to their nuptial pads and throat sacks.

But Brownie is a bit larger and does not have nuptial pads nor a throat sack.

But she acts like she wants to start croaking when I play the sound of Bubba croaking.
But she doesn't make a sound. (that I can hear.) It almost looks like a cat having a hairball.

So do I have a butch frog? LOL
Or is this normal?

Here is a pict of Brownie and Buster.
They have been in quarantine for the past 2 1/2 weeks at my neighbors.
I just put them in with Bubba a day ago and Bubba is completely oblivious to the new
mates.
This AM I heard croaking but it was higher pitched.
When I handled Buster I noticed that his voice is a bit higher than Bubba.

[demon amphibians]

most female frogs don't croak. She may either be reacting to the mating call or she might be a he.