Elizabeth's calculated birthdate would be October 1, 1790. Her first child, Samuel Rodenberger, my 4th great-grandfather, was born to her at age 18 (thanks, Ray for the calculations).
Elizabeth and John (Johannes) had at least 10 children: Samuel, Leah, Rachel, Elizabeth, John W, George, Jacob, Paul, Peter, and Sarah. Samuel, Leah, and Rachel were born and baptized in Upper Milford Twp, Northampton Co, Pennsylvania. After Elizabeth's Pennsylvania birth, the family arrived in Ohio before 1818. John Rodeberger was enumerated in the 1820 Federal Census of Montgomery Co, Ohio. In 1832, John purchased land in Wayne Co, Indiana, an adjoining county to Union Co.
Elizabeth is still a mystery since I don't know her maiden name or who her parents were.
A side note on the value of cemetery surveys. The book mentioned above that contained this vital information was compiled in 1934 [Lacks title page, title information from 4th leaf - from the DAR Library catalog]. Based on the photo of the cemetery on the Find A Grave website, I'm fairly certain that these gravestones would be unreadable today.
Added by: R James