It depends on your definition of plagiarism, but Ruby has admitted to or unintentionally revealed that she does the following:
- Reads and transcribes Sparknotes plot summaries and character descriptions into Notion before reading the text itself. A massive red flag that she doesn't read the book/play that was assigned.
- Splitting secondary essay lists with Blakeney, each reading two essays apiece and swapping notes. Ruby says this is getting twice the results for half the work, but since Ruby's notes are proven drivel, this is a losing proposition for Blakeney, since she'd have to read all essays to make sense of Ruby's notes anyway.
- Sharing Notion access with Blakeney and vice versa, so Ruby has access to all Blakeney's academic thoughts and ideas. Ruby also shares hers, but again, this is worthless for Blakeney.
- Scheduling a "catch-up"/"debrief" session with Ruby immediately after every lecture and seminar to note down all Blakeney's thoughts and ideas.
- Enrolled on all the same courses as Blakeney to ensure that she's be able to benefit from all of the above, since random students would just tell her to duck off if she tried this with them (as has pretty much been the case when Ruby moaned her ass off that members of one of the study groups she was part of did not have Notion for her to crib from).
- Sends numerous, lengthy emails a week to her lecturers full of very leading questions, designed to coax out her lecturer's thoughts, ideas and stance on the essay question assigned.
Given the above, and her general obsession with critical reading, it's very clear that she doesn't read the core text or form her own opinion of it. She reverse engineers and essay from the thoughts and ideas of other people, instead of reading the text, coming up with an opinion herself and finding secondary material that supports and contrasts her ideas.
I'm sure she rewords all of the above extensively, so it may not be the clear definition of plagiarism, but she sure skirts the line as much as anyone can.
It also reinforces that she's learned absolutely nothing from the Oxford rejection. Instead of getting practiced and experienced with the core ability to apply original critical thought to unfamiliar material, she's just done everything she can to avoid using her head for anything but a beret holder.