If she is pregnant, you can see the eggs through the thin white skin of the belly. It will tend to be a bit stretched anyway, which makes it easier. The eggs are actually black and white, so the black bit of them sticks out. Hold her with her tummy towards you and then gently roll the skin across from one side to the other, and back again, to stretch it a little more. The eggs tend to be most visible along the flanks. If she is heavily pregnant, then you won't even have to do that to see them.
As with most animals, if the male doesn't play "piggy backs" with the female, you won't get tadpoles (either type, cheeky!). For breeding purposes they also need a substantial body of water. The water bowl won't cut. Fill the entire base of their cage or move them to an aquarium. The ones you get in WA come from up north and are geared to breed following the storms that begin the wet. So wait till there is a substantial low moving in and then mist their enclosure 3 or 4 times a day while the barometer is falling. On the WA Frogwatch site there are recordings of the male calls of all WA frog species. Record the GTF call and play it to your frogs. The males should respond by calling back and then they will compete amongst themselves. The ratio of males to female you have is good because, surprise, surprise, some females are rather choosey.
If they do lay, either remove the frogs or the eggs. The important thing initially is that the eggs need access to oxygen. So either a wide shallowish container (lots of surface area for gas absorption) or an aquarium pump and air stone, adjusted so as not act like a washing machine. You will know within two or three days if the male was shooting blanks because the eggs will have visibly changed shape if fertile.
There you go... couldn't be simpler!
Blue