Merritt family in upper SC

I have been looking for my great great grandmother's family for over two years. She was born Sarah Louise(r) Merritt in SC in November 18, 1848. She married Robert Calvin Millen in 1869.
I have found lots of Merritt soldiers in Mecklenburg County NC and in SC from that time frame.
The only Merritt census in SC with a Sarah L. Merritt is in 1860 and her age is listed as 6 years. This may be another Sarah L. Merritt.
If anyone knows anything about the Merritts of our area, would you please share information with me?

Thank you.