Have you considered making up your own curriculum? I promise, it's easier than it sounds.
We pull ours together too. I cannot imagine ever finding a boxed curriculum that would work well with the children who are in the higher LOG. There is the asynchrony that you usually have to deal with, and with the boxed curricula you end up buying things at the same grade level. There's also the issue of them learning so quickly that you could be purchasing two years' worth of curricula in one year. That could be quite costly with some of the curricula out there.
We started schooling our then-5-y/o last fall. He had no schooling prior to this, but was already reading well and was very into science. He hadn't been taught any formal math, so we started him with a *fairly challenging) kindergarten curriculum in January of this year. He finished it in three months. It was supposed to last a year.
We then moved up a year and started with
MEP Year 1. Unless he decides to accelerate himself and finishes sooner, he will be finishing Year 1 sometime in August. That's two years of math in eight months of school ---and he doesn't even like math,
at all!
My point is that if your daughters are anything like that in
any of their subjects, you really might do much better, and save money in the process, by pulling together your own materials. If you're okay with neo-classical, then there are curricula like The Well-Trained Mind you could look to for guidance. There are the Thomas Jefferson Education folks, too. Ambleside Online is spectacular for its literary richness. Or, as previously suggested, just find a general list of what they should know by a particular age and pull something together from that. All of these can be looked at for free online, or the first two have books you can read.
I would suggest spending more time on the things that the girls are really interested in so that they can develop their particular interests a bit more deeply. In general, I do think it's pretty easy to pull it all together once you find your style and poke around on the Internet a bit. There is so much free curricula and free help these days where homeschooling is concerned. (I'm sure you know that if you've been doing it for three years! ;))
HTH
