I am still looking to see if I can pinpoint the McAuley connection. Keep in mind, though, that the relationship between the Stewarts (Stuarts) and McAuley families goes way back, probably prior to 1490 in Dumbartonshire, Scotland. To follow this you will need to become familiar with the bloodline of the Ardincaple Macaulays, the Cushendall Macaulays, the Macaulays of Crumlin and Larne, and the Macaulays that settled in Yorkshire. These represent the major branches that I am still doing research on. Please go carefully though my posts on the Macaulay, McAuley, Macauley and McCauley forums. Hopefully, you might find the link that I have missed.
With best wishes, Paul