I am trying to find information on my maternal Grandparents family

Joseph Nelmes b 1831 was married to Helen (nee Constance) b 1834 and they lived at the Pound House Longhope where my Grandmother Helen was born in 1876.

I believe that Helen Constance was born in Mitcheldean to James Constance b 1808 and Harriet b 1820. It is at this point I seem to get stuck.

Any information will be greatly appreciated.