Well if she's not yet a British Citizen then ideally she'd need a Schengen visa for Norway. If the wife of your friend needs one she should apply from the Phils.

Going on the idea of staying on board the ship might sound like a reasonable idea but I've a feeling there's a good chance your wives may be refused embarkation.
Best suggestion is to check with the cruise line itself and secure any positive confirmations in writing.
It's a murky area.

Hopefully you'll update us on the cruise line and their decision as the outcome of these issues are always interesting.

Some countries operate a type of visa-waiver scheme for cruise passengers if the passengers only visit as part of the tour operators organised trip and sleep on board the ship.