The singer is the Eliza that I saw both times I've seen Hamilton (she's actually one of the understudies for all three Schuyler sisters). The second time, King George finished You'll Be Back, and then the lights didn't dim as expected, and we had a pause in the program, after which the headliner Eliza (Chloe Zuel) was replaced with Kirrah.
This filk is clever, catchy, musical, and enjoyable.
Click to view
FTR: Pfizer, AZ, and Moderna are the vaccines available to Australians. Moderna has only just hit our shores, so it's rather amusingly appropriate for "...and Peggy!"
The Sydney production of Hamilton has been cancelled since Sydney went into lockdown - obviously, they can't perform while Delta is on the loose. And the Arts in Australia have been completely unsupported by the government - conservatives who want people to go into productive capitalism, not anything leftist like the arts (or health science, or political studies).
As a result, the creative arts are strongly behind anything that will open up the entertainment sector faster. Right now, the goal is 70% adults vaccinated in NSW to open things up again. As such, the offical Hamilton Australia production has thrown its weight behind vaccination, and so have several of their cast, including Kirrah.