What exactly is it that you are feigning surprise over? That people on high salaries can save a significant sum of money? What's counterintuitive or surprising about this?
Because I'm in tech and have yet to see one of these "high salaries". Nobody seems to acknowledge outside help. Does she have parents that she can always go back to live with if shit falls apart? And then there's a shit ton of "you're living beyond your means, if X isn't true for you.."