Cynthia Herrin is responsible for a number of genealogy records collections for various locations, but it's believed that at least one of them is not credible, namely "Edgecombe County, North Carolina Vital Records, 1720-1880" aka "Early Families of Edgecombe County, North Carolina, Its Past and Present". According to Cynthia, she had found an old genealogy book relating to Edgecombe County, NC, compiled all the data from it and submitted it to Ancestry.com, who accepted it. She then supposedly threw the original book away, claiming it was in poor condition whenever anyone asked her to produce the source and prove her information was reliable. The original book has never been found anywhere else, even by the expert researches at Edgecombe County Genealogy Society. See this topic for more info. Therefore, there is no evidence that this information is reliable.
She claimed the same type of thing with a book called "Bertie Beginnings: The Story of Our County and Its Distinguished Citizens" - see this topic at RootWeb for more info.
And with one called "Our Pioneers: Families of Early Oakland County, Michigan". See this topic for more info.
Most of these have since been wisely removed from Ancestry.com but Cythnia is also responsible for this Fayette County, PA collection which still remains on Ancestry.com. It should probably be removed.
Please comment below if you know of any other dubious collections Cynthia Herrin was responsible for and I will add them to the list.