A friend says she reads The Guardian on Sunday online because she doesn't like the Observer, but is there such a thing?
Surely it is just the Guardian with a few updated articles?
The Guardian, like most newspapers, exist on the 'net 24 hours of the day, 7 days a week these days. Some of them, like The Independent is ONLY published on line.
The sister paper of the Guardian, The Observer, is published in print for sale on Sunday.
So your friend could read the Guardian any time she wishes !