Video likes have an effect on the algorithm. If she has lots of liked videos, delete them. Any playlists she made would influence the algorithm too.
Not sure if video feedback data gets used, but you can clear them too. I’m talking about those “What did you think of this video?”, “Please tell us more” questions.
Edit: I’m not entirely sure if there is an option to delete the “likes”. You might have to manually “unlike” them.
I am getting a little bit of Elon Musk vibe with Linus. Not sure if I’m the only one.