She’ll have to go exchange her francs for Euros or Krona first anyway. Unless you’re going to send her to Switzerland for the morning’s bread...

Worry not.

She will come back with her 5 francs still tucked in her pocket, because it's Sweden. So you will be all set to send her again to the baker whenever you feel like.

This would be the cashless equivalent: https://imgur.com/gallery/swJvdkH

Pre-pay with Swish.

That's how we pay for veggies from farmers. I just fetch 'em at the end of my commute

You can get payment cards for under 18s.

Order and pay for it online probably.