I think science is a hard one to accelerate in school. It requires materials.
DD was fortunate to do a weekly science class at the AMNH for the last 3 years. They are able to do amazing things that no school could compete with. Perhaps you could look within the environment.
There are many science camps and maybe you could find something that fits.
I find it easy to accelerate math and reading at home but science is a different game. When they did earth quakes, they were able to visit the museum display with the seismograph and visually see the frequency of earthquakes in any timeframe and the size. Use the equipment to test the effect of a small earthquake. And this was in grade 2.
My advice is to look around for science advancement.
