Hi John, speaking of "species" it seems most people these days refer to all Antaresia as childrens or just given the wrong names altogether. My first Pygmy Banded pythons were sold to me as Pygmy which I thought meant A.perthensis. Then my first blonde spotted was sold as a childrens.
Now the powers that be have declared all ants are A.childreni, and to further complicate things, A.stimsoni are referred to as Liasis in some but not all states.
I am of the opinion there are 5 species (or subspecies ) of Antaresia
It's over 20 years since all Antaresia (at the time in Liasis) were considered childreni. Recently the stupid specific split between childreni childreni and childreni stimsoni was finally removed, but perthensis and maculosa are still more or less universally recognised. The only amalgamation which has ever taken place in the group was the recent merging of Stimson's with the rest of the Children's.
You'll get idiots getting all sorts of things wrong, but that says nothing about the validity of things. I have no idea who you are referring to by 'the powers that be', but the official taxonomy authority is the ICZN, the international commission of zoological nomenclature.
I am of the opinion that there are three species of Antaresia, but it is entirely subjective. You can reasonably make the case that they are all the same species, you can reasonably make a case for three, but you can't make any sensible case for splitting childreni and stimsoni at the specific level. If you've travelled and observed hundreds of Antaresia all over Australia and you try to make a cladogram of the Antaresia populations to justify this assertion I guarantee you will fail. Cladistically, childreni is a clade within the clade of stimsoni (not that such a clade exists in the taxonomical nomenclature). I'm guessing you're including Pygmy Banded Pythons as one of your five, but if you travel Australia extensively you'll find multiple populations of Antaresia which would just as validly be put into their own species, so to include them you would need to accept many more species.
A fun thought experiment is to consider that if we consider splits like childreni/stimsoni to be valid at the specific level, by the same standards we would have dozens of different species in what we currently consider to be living humans (comically, they had to change the rules on taxonomy for this reason, I was very amused as a university student 20 years ago in my genetics lectures looking at the definitions which clearly showed it was not possible to classify some populations as human... they changed the rules a couple of years later).
Either way, your snake is clearly an eastern Cape York Antaresia, which pretty much anyone worth talking to including yourself considers to be Antaresia maculosa, not A. childreni. Very few people these days still consider all Antaresia to be 'Children's'.