I have been lurking on the HOD forum since the fall and I finally decided it was about time that I post

However, what to use with dd7 is not as easy of a decision. She is doing a wonderful job with Bigger...and she placed in Bigger when we began {ds10 placed in Preparing but I wanted to combine them for our first year with HOD}. However, I am not sure that she is ready for the move to Preparing, although she might be by the time we finish Bigger this summer. I also don't want to continue to combine ds and dd just because...For one thing, dd7 is a beginning reader, she is doing a great job with the Emerging Reader's Set this year, but I am not sure she will be ready to tackle the independent reading that she will need to do for Preparing.
So...can I do Preparing with both kiddos but at different speeds ~ having ds10 work at regular pace and finish in one year, have dd7 work at half speed with me and planning to finish in two years? I would prefer for dd to continue with the 3Rs daily, she is doing a great job with R&S2 and her math program. And if I do this, would it be preferable to purchase some duplicates...especially the Preparing Guide so ds can have his own copy, and maybe the Child's History book...
Any thoughts? I'd love some input

Oh, I also have another ds...my sweet 5yo who will be using LHFHG.
Thanks! Wendi