Not to sure where you got your information, but Barbara McCOMBE is the daughter of Andrew McCOMBE. Andrew McCOMB's wife was NOT Jane/Jean REABURN, the name "REABURN" isn't in John's will anywhere.
I agree Barbara was the daughter of Rebekah Jane (Young) McCOMBE but her father was Rebekah's husband, Andrew. From Chalkley Chronicles: "pg 541-5Andrew McComb's will proved; Jane, the widow, refuses to execute it. June 17, 1788." http://www.rootsweb.com/%7Echalkley/http://www.rootsweb.com/%7Echalkley/
I have the wills of John Sr. and all his children; Jean REABURN b.is the 1st wife of Thomas NICKELL, II, grandson of John Sr.
Not to dispute General Joe NICKELL, but I feel Demoy has done an excellent job of interpreting the Wills of the family and putting the children in a different order than General Joe had them--or General Joe's professional genealogist.