If Joey wasn't the big brother of his family, he would probably be more laid-back. He's already pretty distant, and prefers sleepy quiet days at the beach over more intensive work or interaction. However, growing up being told to "set a good example" has led him to work harder and try to keep focused on finishing his tasks, one at a time. This has improved his speed at finishing homework assignments, for instance, although it hasn't actually helped his grades any. The main area it's helped him in is socially: years spent with his baby sister have molded him to be patient and more engaging, if still not too invested in others' personal lives, with the exception of his handful of close friends at primary school. Attending school in America is going to be weird, and Joey kinda wishes that his parents had decided on the New Zealand Academy of Magic instead, because then at least he could stay on the same continent and keep practicing surfing with his dad on weekends. That's going to be a bit harder to do in Colorado...
Physically, Joey takes entirely after his mum ("and mentally, too, if you're lucky" - quote also courtesy of his mum. Because, as she's sometimes mentioned with sideways eyerolls at Dad, "book smarts can only get you so far!"). His bowlcut is straight and dark, his eyes are heavy-lidded and dark, and his skin looks tanned from a distance but actually it's just also naturally dark. With slight, delicate facial features, including an almost upturned nose that has been referred to as "boopable" by both his grandmas (well, his mum's mum had used a Thai word that he didn't know but it had been translated for him as basically meaning the same thing), his baby pictures are nearly indistinguishable from his younger sister's. Currently his wardrobe is as well, though that's mostly because she gets his hand-me-down tee shirts and jeans, and presumably she'll get his robes once he's outgrown them too. At least he's still bigger, if only by a few centimeters.
Born out of wedlock to May Nguyen, second-gen of an immigrant family from Thailand and journalist for The Sydney Morning Herald, and Cooper Blair, a pureblooded Ozzie and the (not self-proclaimed but not self-denied either) dumbest aerospace engineer around, the childhood of Joey Blair can best be described by the baby kangaroo his nickname unironically references. His early years passed in very close proximity to his family, growing up in his aunt Estelle's sometimes too cozy flat with his sometimes too hot-and-cold newlywed parents. The arrival of his little sister Paige coincided with his aunt's wedding, the monthly allowance for renting her flat was put towards buying it, he flailed through kiddie swim lessons and bounced from daycare to primary, and along the way they discovered that one thing he had inherited from his dad's Pureblood lineage was his magic - which in turn required May to find out what a Pureblood lineage even was. Somehow the fact that Cooper had accidentally kept his Magical World secret for years didn't result in them getting divorced. Miraculous, really. And now Joey's off to RMI! Hooray!