My daughter has done really well learning to narrate with Aesop…to the point that I’d suggest using part of it at least now, and part of it next year. (Haven’t done Mod 2, but I believe it only uses selections from Aesop, and not the whole thing? Maybe someone can correct me on that.) She’s also done well narrating from the Christian Liberty Nature Reader (the first book), although she reads this by herself, it’s not something we read together. I like both of these b/c they are short and sweet and so you can read the whole thing in one go before asking for a narration. My dd doesn’t really like it when I interupt the story to have her narrate, so starting with very short selections (rather than ones we have to break up) has been a key part of progressing in narration without too much frustration on her part, in our experience anyhow.
If not…Fifty Famous Stories (or the companiion Thirty Famous Stories) are probably the simplest other option you mentioned. We’ve read some of these this year and my dd has done all right narrating them. But they are longer so you’ll have to break them up, probably.
I’d save Parables from Nature until your child is older, personally. We started to read it this year and while my dd liked it, they were difficult to follow and definetely too difficult for her (as a beginning narrator) to narrate. I felt like she would gain more from reading this one if we saved it for a few more years.
Hope that helps some.
Jen