Twilight reads books and likes it; even Starlight knew of it, while she made an effort not to call her out or call her names.  Hurting a Princess has bad consequences and hurting a friend is terribly wrong.

She thought it was safe to keep tabs on her reading habits and occasionally copy one of the books she had seen her read.  This does sound good.

Of course, this is all about what happened, when Starlight dives into one particular book she just had copied for her Starlight wing in the back of Twilight’s personal library.