I couldn't find any Lucy Jane Pieratts in the Pieratt family so I searched Ancestry.com and RootsWeb.com and found some information.
There was a Lucy Riddle who was born ca. 1832 in Bath Co., KY, the daughter of John William Riddle (1808-1887) and Mary Adeline Myers. She was married to David McClain.
Other children of John and Mary are:
(This info comes from Ancestry.com's Gene Pool Individual Records, which is a mixture of birth, death, marriage, and other records that should ALWAYS be verified by the actual documents. This is just a rough draft.)
Nathan RIDDLE (born Jun 1836 @ Bath Co., died 1901 @ Rowan Co.) m. 13 Aug 1858 @ Rowan Co. to ?
Lewis Henry RIDDLE (born 1837/38 @Bath Co.) m. 27 Oct 1858 to Mariah Clark
Mary Susan RIDDLE (born 14 Aug 1839 @ Bath Co., died 1900 @ Rowan Co.) m. Abraham Butterfield
Martha Ann RIDDLE (born 14 Aug 1839 @ Bath Co., died 1900 @ Rowan Co.) m. 1859 to John B. Clark
Commodore RIDDLE (born Aug 1847 @ Bath Co.) m. Amanda Nickells *There have been many Nickell-Pieratt marriages (my own great-great-great-grandparents were John "Long John" Smith Pieratt and Margaret Harrison Nickell), but I don't know if this Amanda Nickells should be Nickell (without the "s"). There is a great-granddaughter of John Nickell (1771-1849) and Elsy (Wilson) Nickell (1768-1851) named Amanda Nickell who was born in 1852. I don't know if there is a connection.
Nancy RIDDLE (born 17 Mar 1848 @ Bath Co., died 12 Jan 1927 @ Rowan Co.) m. 1866 @ Rowan Co. to Tony Earl Butterfield
Sarah R. RIDDLE (born 9 Nov 1851 @ Bath Co., died 1 mar 1933 @ Rowan Co.) m. 23 Feb 1871 @ Rowan Co. to William Thomas "Buddy" Hall
John William RIDDLE (born 3 Jun 1855 @ Morgan Co., died 27 Mar 1942 @ Rowan Co.) m. 1 Jun 1874 @ Rowan Co. to Sophia E. Thomas
You should search RootsWeb's World Connect Project (just go to http://www.rootsweb.comhttp://www.rootsweb.com) and click on their WCProject. I found John William RIDDLE (1808-1887) there. You should contact the person who submitted the info and compare your info. I don't know where the Pieratt name would fit into this family. Possibly they were cousins? Also, you should post your query at the Riddle family Gen Forum page to see if there are other Riddle researchers out there.