Mr Justice MacKay adjourned Smedley's sentencing to a date yet to be fixed for the preparation of a pre-sentence report, and remanded her into custody.
He told her: "I want you to understand that you stand in very real peril of a prison sentence as a result of this conviction. Don't have any delusions about it."
More top news
The tourists had no idea they were about to be dropped off at the star-studded ceremony to meet A-listers.
It comes just weeks after actor Michael Keaton confused the names of films Hidden Figures and Fences at the Golden Globes.
All eyes were on the stars as they arrived on the red carpet for the 89th Oscars. But who won in the fashion stakes?