Hi Jean, I could find no marriages for Paisley in FreeRegUk. Their volunteers haven't tackled those records yet. Sometimes books on the history of the place will also include marriages or perhaps there are family history books for one or more of these families? Internet Archive is a great place to look for both types of books. Also, have you tried FamilySearch.org? Sometimes their records will have more information. A final thought is looking at the families with cluster research to see if any records of Mr. Kirkland's family, her own siblings, and families of both sets of possible parents include either Peden or Aitken.
hope this helps!