Ugh.... well, I guess that I'd try to address the underlying social reasoning rather than automatically accepting "I don't want to" on that basis.

Would she be okay revisiting material that she's got mastery of? What will be going on with her sibling? It's possible that neither one of you (yet) has a complete picture of things, so I wouldn't necessarily lean toward no.

Is she willing to keep an open mind?

Schrödinger's cat walks into a bar. And doesn't.