Hi. It sounds like your daughter will do all right academically no matter what, so your challenge is really to help her not waste her time when she feels like learning. I would join some home schooling groups and find one or more curriculums to work with, to make sure she is well-rounded as she progresses. Singapore Math, EPGY, etc. are well-respected, for instance, and you could supplement with a wide range of fun math materials.
On science, I'm not so sure of where we're going to go yet. explorelearning.com has some cool applets (small applications) for illustrating math and science concepts. We've been working through a science workbook that's supposedly a thorough treatment of science at around a fourth-grade level, but it seems pretty basic to me. I think that if you got hold of a good science curriculum and were up for buying actual textbooks, and actually did some explorations and experiments, and adjusted to add material to help her go in whatever directions she showed strong interest, you'd be doing well enough at this stage. There are some pretty good science kit toys out there for self-directed play (google "Thames and Kosmos" for starters), but unless the knowledge is fit into a framework, it might result an uneven foundation. You can also join some online places featuring lesson plans, and supplement with free stuff like Wikipedia. DS5 has learned lots of science so far using Wikipedia and branching out from there.
If you're going to let your daughter use the web, make sure there is safe-browsing software installed. It's my experience that my son can go somewhere not on the preapproved path if I turn my back for a trice.
I guess the main thing I'd be looking at is mail order to supplement the web, at this stage. It's a shame the library and island in general aren't better equipped, but that's the way it is. You'll wind up spending more money, but otherwise should face roughly the same set of challenges faced by home schoolers everywhere. You just can't as easily find a local museum, play group at your level, etc.
