I can't see a marriage in Buckingham, but there are two baptisms for 2 children, and a burial for a William Kibble.
3 Jan 1804 - Marey Ann daughter of William & Frances KIBBLE.
24 Aug 1807 - Eliza daughter of William & Fanny KIBBLE.
Burial - 27 Oct 1812 William KIBBLE. no age given.
No burial or marriage for a Fanny KIBBLE(as a Widow), in Buckingham @ St Peter & St Paul.
No baptism for William Kibble or Fanny/Frances Edwards.
I would ask BucksFHS for a burial & marriage search for Frances/Fanny.
Steve.
Taken from BucksFHS - St Peter & St Paul. Buckingham. Transcripts CD.