"Percival Hall2 … m., in Woburn, Oct. 18, 1697, Jane, dau. of Thomas and Grace (Tay) Willis, …"
This is apparently an error on the part of Mr. Hall. According to the Woburn Vital Records, on this same page, Percival Hall's brother Stephen married, at Woburn, 18 October 1697, Elizabeth Willis, Janes sister.