Okay let's assume the lady has bitcoins on her non-custodial wallet but she still needed to sell it for fiat because the hospital doesn't accept BTC. What if she tried to trade it on a centralized exchange and the platform suddenly froze her account for some reason? That's still going to be a problem. How about P2P platforms? A lot of them requires bank accounts for trades so the same issue.

The point here is that there is always a risk as long as people continue to use centralized platforms.