Thanks to tulipwarrior who’s alerted me of the video!
Katie’s brother Rory has made a video project for a job application a couple of years ago (?); Katie and other few people appear in the last minute of the video making a shushing gesture. It’s only for a few seconds and I’ve uploaded Katie’s few frames here in case you wish to gif it too.
She’s asked me not to link to the video to preserve Rory’s channel from being assaulted by Katie fans xD, hope you understand ;)