Hi
1841 census has Charles as an only child, aged 7, living in St Peter Port with his confectioner father, Robert, aged 30, and Mary, also aged 30.
Robert was apparently England born and they are living with a James & Rachel Ozanne (possibly Mary's relatives)
I will see if I can find if there are any other children though
1851 has got Robert remarried to an Elizabeth with Charles having a step brother - Henry A Adams.
At least from the census it doesn't look like he had any siblings.