there are a few years of missing marriages in Lonan (marr reg lost + gaps in Bishop's transcripts) - this probably explains a missing marriage - isn't Ann bapt Lon 1796-12-18 (reg just gives fa as wm killip + no additional note)
as Wm + Janes 1st child was prob Jane in 1789 then their marriage was probably 1788 which is one of the missing years.