We just read about William and Caroline Herschel who discovered Uranus in (I believe) the 1780's (we read about them in our Astronomy book). It's fascinating, really-they were homeschooled by thier father who taught them music (he was a musician), mathmatics, and Astronomy. William enjoyed making telescopes, which they sold for extra income when they moved from Germany to England to work in a theatre. Once they figured out Uranus was a planet, not a comet, they were asked by the government to be full time Astronomers. Cool story-especially considering Caroline, who was educated against her illiterate mother's wishes-she wanted her daughter to stay illiterate and serve her. Also of note is that they were the first to discover a planet in many hundred years and they were Christians who wanted to not name their planet after a false god. That didn't work out, obviously, but they went on to discover many other things, and their discovery of Uranus led to the discovery of Neptune.
My daughter (8) really thinks it's neat that they were homeschooled kids . I looked online and it looks like there have been many works done especially on Caroline Herschel. I'm sure your librarian could help you locate some wonderful books on one or both of the siblings.