Alexander Livingstone and Isabel Hunter had four children baptised in Falkirk between 1617 and 1622 - Elizabeth, Robert, Hew, and John. Sources from Scotland Baptisms are on Familysearch e.g.
"Scotland Births and Baptisms, 1564-1950," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:XT2M-HFV : 10 February 2018), Allexander Levingstoun in entry for Hewgh Levingstoun, ; citing Falkirk, Stirlingshire, Scotland, reference 2:17TSGSR, index based upon data collected by the Genealogical Society of Utah, Salt Lake City; FHL microfilm 1,041,942.
I can't see any source for a marriage but I would be looking in Falkirk about 1615 on that evidence not Londonderry 1622. Perhaps someone has estimated the marriage from John and did not know of the earlier children? I cannot see any connection of this couple to the earl of Callendar/Linlithgow mentioned on the page; they are quite well documented and no mention of an Isabel Hunter, or of the name change to Boggs. Quite a lot to work on there!