I'm not disputing that she's likely upper middle class, but could she just have relatively expensive habits? I'd be shocked if she's paying anything and she probably has a NIL deal or two so she could be getting spending money from that; her parents could also be giving her a large allowance as they're not paying anything.
But I can't wrap my head around her getting scammed out of $20k, let alone through CashApp - I never had that much money on hand and sure as hell wouldn't send 40 credit card payments all of $500 dollars. Maybe if I liquidated most of my trading accounts I could (I mostly got lucky with one stock that grew a lot - I only started with $5k) but I can't imagine not seeing that something is amiss.