Hi Andrea
Only just spotted your post (I'm a new member).
I may be able to help a little. Here's what I have -
Abel Mead (1807-1876), was my great great grandfather. Born in Chesham, and married in 1827 to Eliza Atkins (1805-1868), also born in Chesham.
I have Abel listed as having a brother William (b1812), and a sister Sarah (b1804). Their parents are (I think), William Mead (b1780) and Sarah (b1780). Sarah's maiden name unknown.
Abel & Eliza had 8 children (all born in Chesham), Sarah (b1829) William (1831), Ann (1834), Edwin (1837), Thomas (1840), Eliza (1842), Abel (1846), and Stephen 1851).
Of course there could be other children, and some of these dates might not be 100%, but hopefully this may be of some help to you.
My main sources are Ancestry and historical family information.
kind regards
Rich