Harris family line??

Hi there!! I am looking for information on a Catherine Harris listed from PA born 1699-1700 died 1789 in Montgomery Co. VA. She married Robert Sayers (1700-1746 and they settled in what is now Augusta Co. VA. The had children William Sayers (1728-1781, Alexander Sayers (1731-1765), Ann Sayers (1735_), Margaret Sayers (1737-1811), and Elizabeth (1736-). I have many documentation from Augusta Co. VA court house relating to Robert and his son Alexander which is my line. I am unable to find any information to who is Catherine's parents. I have seen where many believe she is daughter to William Clariborne Harris and Temperance Overton but have no proof to support that claim. Any clues will be so appreciated!

Raven