In order not to miss crucial plot points, Roy increased her attention towards Vivian.
For example, at the drama club, she often interrupted Vivian's meaningless busy actions, inviting her to sit down, rest, and have tea. Another example, when searching for books in the library, she occasionally greeted the focused Vivian and solved her minor academic troubles.
Other times, Roy didn't need to expend much effort. It's too easy to supervise someone at the academy; just utilize a bit of gentle acting, a few reasonable words, coupled with the Derek family's formidable power and wealth, and naturally, many were willing to be Roy's eyes.
Vivian is no Theodore; she's unable to hide her whereabouts. Like a gray sparrow without any self-protection ability, living in an invisible cage for others to admire.
Roy is the spectator outside the cage.