*sister of Neil Earl of Carrick

*Duncan 1st Earl of Carrick
born about 1174 Galloway, Scotland
died 13 June 1252

*Avelina FitzWalter
born about 1179 Scotland

*Neil Earl of Carrick born 1202 Carrick, Galloway, Scotland died 1256

*William "Long Legs" of Douglas
born about 1210/20

*Sir William "le Hardi" Douglas
born before 1256
died 1302

biographical and/or anecdotal:

notes or source:
All the entries state that the wife of *William "Long Legs" of Douglas was the sister of the Earl of Carick.
*Duncan 1st Earl of Carrick was born 1174 and that would make his sister approximately 60 years older William.
Duncan's son was *Neil Earl of Carrick who was born 1202, so his sister would be marriageable to William.
Neil's daughter Margaret married *Robert le Bruce who was born 1243. He then became Earl of Carrick.
Robert's sister would be 40 years younger than William.
Therefore by elimination she must be Neil's sister and Duncan's daughter.