I have made a preliminary tree for the Rev. David Richards. He married Margaret Morice, C1759.
They had 4 children; Richard and Mary, (1760-twins. Richard died in 1761),
Mary married James Morice, (1765-1839), in 1783. They had a daughter, Mary, (1790- 1866). (She is the "Eviction if you don't go to church" lady.)
Elizabeth, (She married James Morice and had a son, Stephen).
The Rev.Thomas, He married Frances Porter in 1792. Frances was the sister of Edith Porter, the writer of the Jane Austen book that you refer to.
I have the 'Jane Austen' file and the 'History of West Wales' if those were the ones that you sent the links to.
regards, Peter