Article June 2017 in the Scottish Genealogist, “Queen Euphemia and her ancestry,” TSG LXIV(2):49-52 by John Ravilious
http://www.academia.edu/35370666/Queen_Euphemia_and_her_ancestry_TS...
“most likely a daughter of Sir John Graham of Abercorn & Dalkeith, born say 1275, and sister of Agnes (Graham) Douglas.”
Is this Sir John on Geni already ?
I believe this Sir John de Graham of Dalkeith, Abercorn and Eskdale was Margaret’s father, according to Ravilious