This is not a novel concept but the difference in Zoey's upbringing vs Rumi's and Mira's is so funny.
Like, Rumi was likely homeschooled and Mira either was also homeschooled or went to some fancy prep school. Zoey went to a public school that probably had roaches and questionable fountain water.
Rumi was raised for stardom. Mira grew up with a trust fund and credit card in her dad's name. Zoey probably worked at McDonald's for gas money. Fully has a customer service voice and an undying hatred for people that walk into restaurants right before close (Mira and Rumi used to do this without thinking about it and she does NOT let them anymore).
Zoey might be the only one of them that actually knows how to drive because the other two would've had people driving them everywhere for most if not all of their lives.
She's the only one with an actual concept of money. She'll be like "DAMN that's way overpriced for the amount of food you're getting" and Rumi and Mira are like "oh is (Korean equivalent of like 50 USD) a lot for this?"
She may also be the only one who knows how to manage chores. Like, maybe Celine had Rumi do chores to teach her the value of hard work, but maybe she skipped that in favor of more training. Mira absolutely had people for that. Zoey was doing dishes as soon as she was old enough to learn how. She probably feels weird about Huntr/x having people that they pay to clean their place for them every couple weeks because she was NOT raised to sit around while someone else does the chores. If her parents were doing chores she was always helping.
For a while she probably forgets that she just has crazy money now. She sees something she wants and she's like "hmmm, maybe I'll get it in a few months to make sure I REALLY want it and can justify the purchase better" and the girls are like "?????? But you want it today. Just get it. We could literally buy this entire store."
