I have a little bit of info on the same John McPherran, from the wills and legal documents of other family members. John married twice, and one of these women was named Martha. The other wife's last name was Sterling, and she was the daughter of Sanders Sterling of Scotland. My family's records have her listed as 'Rebecca Sterling' in some places, and 'Mary Stirling' in others, but I can't find anything else to back either up. Sterling was (rumored to be) a descendent of the royal line of Scotland.