On Ancestry, all the charts say that the parents of John Trevallion Stewart are John Stewart and Ann Cooke. Unfortunately, I cannot find any proof of their existence to add them to Wikitree. I did find a will of a John Stewart that mentions a minor child named John as well as several other sons. The timing is right but I cannot tie this John or his brothers to John Trevallion Stewart. I tried following property ownerships but I cannot connect the dots. It looks like this is the right family as the lands mentioned in the will are in close proximity to where later generations are buried. The Ancestry birth dates look wrong but that is not really a surprise.
