Twins
The 11th and 12th children were twins, born about 1851, lived only about a month. Henry Clay's letter at Family.pdf shows them as daughters. This confirms the middle names of John Henry's last two sons.
Hilyard Blanton
Hilyard (Hilliard) Blanton was born May 15, 1854. He died June 7, 1880 at the home of "Johnny" [presumably a nickname for Joshua] Howard Starr from choking on elderberries. See Hilyard Blanton.pdf