The clues certainly match up as the 38-year-old is a classically trained opera singer (which would fit with those "Italian" roots) and despite being nominated for an ARIA Award on 13 occasions, is yet to win one.
When the Queen took to the stage with a dreamy version of The Weeknd's Blinding Lights, though, that seemed to be the final clincher - at least in Twitter's eyes.
"I’m so confident that the Queen is Kate Miller-Heidke that if it’s not her I’ll shave my hair off," one brave viewer tweeted.
"I KNOW THOSE HIGH NOTES! DEFINITELY KATE MILLER-HEIDKE," another exclaimed.
Along with four studio albums and three live albums, Kate also co-wrote the music and lyrics for Muriel's Wedding: The Musical which could be another reference
She also performed her song Zero Gravity at the 2019 Eurovision Song Contest in Tel Aviv, Israel and placed ninth overall.
The song detailed mum-of-one Kate's battle with postnatal depression and told TV WEEK: "It's definitely empowering to take something that's personal and vulnerable and to turn it in to connection with people."
"I do feel the song goes to those dark places, but ultimately it's an empowering song to sing, and hopefully to hear, as well."
Perhaps these "highs and lows" are in reference to her Eurovision song and daring performance swinging around the stage?
The first character to be revealed was Echidna who turned out to be tennis champ Mark Philippoussis.
The triple Olympian sung his rendition of George Michael's Faith and panellist Jackie O even guessed that he was the man behind the mask before the big reveal.
“I was bummed, I’m gonna be honest, I am competitive. Who doesn’t love to sing? I love music, it was an incredible adventure,” Mark told host Osher Gunsberg and panellists Jackie, Dannii Minogue, Dave Hughes and Urzila Carlson.