EandBMom -
Welcome!
From what I understand, the rhetorical skills questions are part of the English section of the Explore. Supposedly it tests the more intuitive skills in writing, not necessarily the mechanics. So, maybe you could explore an on-line writing class for your daughter, or a language class (Greek/Latin?)

If her overall scores qualify, I would suggest the Gifted Learning Links from Northwestern University. There are on-line classes that are self-paced (I'm only familiar with one of the science classes, but you could check out the writing classes or other humanities classes).

http://www.ctd.northwestern.edu/gll/courses/