First, I'd want to know two things: 1) how much acceleration does she need in this area, and 2) what does the typical 4th grade curriculum for LA look like at her school?
I've never had a kid in a traditional classroom for LA in 4th grade, so I'm not positive what to expect from that curriculum, but I'm imagining that it would include some book reports, general writing practice (grammar, structure, spelling, etc.), and maybe groups of kids who are working on reading the same book (book group type of thing). If it is something like this, would it work to simply ask for harder books, more advanced writing prompts that ask the writer to utilize higher levels of Bloom's taxonomy, harder spelling lists, etc. Perhaps bringing in some of the materials from the 5th grade would work for some of this.
This brings me back to my first question. Would the standard 5th grade LA curriculum be adequate? If she needs high school level LA work (reading level, level of abstraction and depth), then that type of thing might not be adequate.
Another thought, are there any other kids in her class next year who have similar needs to your dd or is she far and away more advanced than the highest group? If there is a reasonable peer group, they might be more willing to have those kids all working together on 5th grade material, if that is appropriate.
