I reckon this is their Marriage. allowing for Dialects Civility could easily become Sibelly thence Sybil or Sibbell.
JohnShrubsole married Civility Kemp ,12 Jan 1699 at Canterbury, St Alphege
John's Parish parish Whitstable His Occupation Carpenter
Source
Archive U3/8 Page141 Canterbury Cathedral Archives
Record set Kent, Canterbury Archdeaconry Marriages