This is My family tree that seems to very closely mirror your tree.
My great Aunt Lavinia was known to keep in touch with distant relatives in the USA but would not share the details. (some long past feud between the sisters)
Martha Palfrey = George Palfrey
Son 1 David John Palfrey b 1859 d 1920 m oct 23 1883 to Miriam Thomas (David's Birth Cert gives mother as Martha Palfrey late Banks formerly Thomas)
Miriam Thomas b1865 d 1927
Son 2 Henry Palfrey b 1864 (no further infomation)
David and Miriam Chilren That I have found
1 Mary Jane Palfrey b 1889 Married Alfred Lewis Davies (my grandparents) 2 John Palfrey b 1891 3 Elizabeth Ann Palfrey Married John Owen Thomas 4 Miriam Palfrey Married William Richards 1917 (Killed in action 1917) 5 David James Palfrey b 1899 d 1899 6 Martha Lavinia Palfrey 1902 - 1996 Married Albert Trevor Griffiths 7 David William Palfrey b1903 8 William George Palfrey 1905 - 1921