It is true that if you put money in the exchange, there are some risks. Even if you trust the proceeds of the transaction, you must be careful to leave a way behind. You can tell her some of the benefits of putting it in a hard wallet. If your friend disagrees, you can let him put it. A small part of them are on the exchange, and if they are really "hacked" or "disappeared", they will be deemed to pay tuition. So he won't do it next time