maynard on Family Tree Circles

Hi I am researching the Maynard family from Kent, and am at a brick wall, i can't find any registration for my 3x gr grandfather born about 1804 ? Kent. His wife ( no proof of marriage either) Martha Lee born in Seal Kent 1809. they had children Eliza b 1833, William b 1837, Thomas b 1839, Mary Ann b 1840, Elizabeth b 1844, Esther b 1847, Charles b 1849, all born in Sevenoaks Kent. The family emigrated to Australia in 1852 aboard the "Helen" with children William, Thomas, Eliza, Elizabeth and Charles. Anyone got any hints as to where i go from here? I don't know Who Charles's parents were. Any help would be appreciated.

Cheers Maynard

Charles Maynard b 1804c ? born in Leigh Parents unknown
spouse Martha Lee b 1807c ? born in Seal, parents ? Jonathon Lee and Martha Mitchell

Children

Eliza 1833 b Sevenoaks
William 1837 b "
Thomas 1839 b "
Mary Ann 1840 b "
Elizabeth 1844 b "
Esther 1847 b "
Charles 1849 b "


Family migrated to Australia in 1852 aboard the ship "Helen"