I think it would depend on your goals & hers.
My 17.5yoDD opted to CLEP out of American History I (and thus earn college credits) so we went a particular route.
Separately, and not planned as a go-along, she also is working through (and nearly complete, with just one unit left) of Excellence in Literature’s American Literature study Honors Track. She’s read a nice assortment of classic American authors, learned about the authors and the time periods, written analysis on the works as well as various other types of writing assignments. No, not particularly CMish in nature, admittedly, but she knew what she wanted for literature and this fed her needs. (She is a book-hound. ) She’s not yet decided if she will take the CLEP for American Literature or not, but with a bit more studying of time periods-authors-titles, she would easily pass.
As far as pace (per book or per quantity of pages…) That’s a tough one, IMO, as it would depend, as i’ve said, on the goals as well as on your daughter’s desire for meaty literature.
