Orkney Image Library

Some clues in the photo: the photographer was J Kelly of Perth; most of the nurses are wearing red crosses; the patients are in hospital blues and look more convalescent than sick; the headgear is Great War style; the building doesn't look like a purpose-built hospital.
Several auxiliary hospitals were set up in the Perth area in WW1, one of which was known simply as the Perth Red Cross Auxiliary Hospital.
Probably none of the above will help you Myrna, even if it's accurate, but it suggests someone indirectly connected to you 'copped a Blighty one' in WW1. The date is probably a little earlier than 1920.