*Isabella (Matilda) of Mar
born about 1278 Kildrummy Castle, Kildrummy, Aberdeenshire, Scotland
died about 1320

father:
*Donald 6th Earl of Mar
born about 1240 Kildrummy, Aberdeenshire, Scotland
died after 25 July 1297

mother:
*Helen (Elen) verch Llewelyn
born about 1230/34 Wales

siblings:
Margaret de Mar born about 1270 Mar, Aberdeenshire, Scotland died before 24 July 1326
Garnait Earl of Mar born about 1272 Kildrummy Castle, Kildrummy, Aberdeenshire, Scotland
died before September 1305
Duncan of Mar born about 1274 Kildrummy Castle, Kildrummy, Aberdeenshire, Scotland
Alexander of Mar born about 1276 Kildrummy Castle, Kildrummy, Aberdeenshire, Scotland
Mary of Mar born about 1280 Kildrummy Castle, Kildrummy, Aberdeenshire, Scotland

spouse:
*Robert I "The Bruce" King of Scotland
born 11 July 1274 Writtle, Near Chelmsford, Essex, England
died 7 June 1329 Dunbartonshire, Scotland

children:
*Marjorie Bruce Princess of Scotland
born about 1297 Scotland
died 1316

biographical and/or anecdotal:

notes or source:
LDS
ancestry.com
"Biographical Encyclopedia of the Kings & Queens of Great Britain" by Mike Ashley