*Marjory Maddadsdottir
born Caithness, Scotland

father:
*Harald II Maddadsson Earl of Orkney and Caithness
born 1130 Caithness, Scotland
died 1206

mother:
*Gormflaeth MacHeth
bo1rn ab1out 30 Moray, Scotland

siblings:
David Haraldsson Earl of Orkney
John I Haraldsson Earl of Orkney

spouse:
*Gilchrist 4th Earl of Angus
born about 1154 Forfar, Angusshire, Scotland
died between 1207/11

children:
*Beatrix of Angus
born about 1184 Forfar, Angusshire, Scotland

biographical and/or anecdotal:

notes or source:
LDS
ancestry.com
It is not clear from the sources why she was not called Haraldssdottir.
From this (discounting the dates) she could be Harald's sister?