Using Classical Comp with a reluctant writer

[homeschoolmom16]

I am looking into using the 4th grade curriculum pkg. with my dd for next year, but I am trying to decide if she's ready for Classical Composition. (She's has a fall birthday, so she's a little young for her grade.) We used Writing with Ease in 1st and 2nd grade, and tried Writing Tales this year, and my dd has done good work with these 2 programs. She can generate sentences, summarize a passage, and retell a fable in her own words, but she hates to write. If we did the whole thing orally, and I didn't require her to write any of her answers on paper, I think she'd be perfectly happy. She is an excellent reader, but not a very good speller, so I think her lack of spelling ability is part of the problem, especially when she has to write from dictation.

I looked at the MP 3rd grade grammar book samples, and based on what I saw, I think my dd would be able to do just fine with that book now. Also, we just started using the MP 3rd grade literature guides, and she can do the writing that's required in those, but she grumbles about it. How big a jump is it from 3rd grade writing to Classical Comp? I was a little intimidated when I looked at the samples from the Fable book. Should I try it next year, or are we better off waiting until 5th grade? If I do wait another year, what should I do for writing next year?

Thanks!
Sue