Margaret of Mar, Lady Sutherland (4th) - What's the source she married all three men?

http://fmg.ac/Projects/MedLands/SCOTTISH%20NOBILITY.htm#IsabelMarMR...

5. [MARGARET of Mar . She is named as wife of Malcolm Earl of Lennox by Fraser[534]. She may have been the daughter or the sister of Donald Earl of Mar. m MALCOLM Earl of Lennox, son of MALCOLM Earl of Lennox & his wife --- (-killed in battle Halidon Hill 19 Jul 1333).]

[534] Fraser, Sir. W. (1874) The Lennox, Vol. I, p. 240 (not yet consulted), cited in CP VII 591.

We should check TCP & TSP, but it’s looking like we will need to detach Margaret of Mar Malcolm, 5th Earl of Lennox

Thoughts?

N.N. Lennox Is not a known daughter of Malcolm ll, is she?

• N.N. Lennox (AKA Helen Forrester, countess of Lennox) wife of Duncan de Atholl of Glenerochie, Earl of Atholl - sources added to profile, detached as daughter of Malcolm, 5th Earl of Lennox
• More citations added to Malcolm ll, including links to Fraser & James Balfour Paul with their notes that his wife is unknown. Detaching him as husband of Margaret of Mar, lady Sutherland (who should have had a sister Margery)
• TSP shows 3 sons, Fraser shows 2, and Geni shows one - Donald, 6th Earl of Lennox Murdoch (Muireadhach) and Malcom lll seem to be missing.

I retrieved the 2nd Margaret of Mar:

wife of Malcolm Lennox

https://www.clanmacfarlanegenealogy.info/genealogy/TNGWebsite/getpe... shows as daughter of Garnait (Gratney), 7th Earl of Mar & Christian Bruce, Lady of Garioch (Carrick), an also describes a theory that she was a Mor, not a Mar.

https://www.clanmacfarlanegenealogy.info/genealogy/TNGWebsite/getpe...

1 - Malcolm fifth Earl of Lennox married a daughter of Christian Bruce (the king's sister) and sister of Donald earl of Mar.

2 - It is merely speculation that Margaret Countess of Lennox (wife of Malcolm V Earl of Lennox) was a sister or daughter of Donald Earl of "Mar", I suspect this was a mistaken identity for her being a sister or daughter of Aonghas "Mor", father of Angus Og mac Donald? …

It is not improbable that rather than her being related to the family of "Mar," Duncan's grandmother Margaret Countess of Lennox was perhaps a sister or daughter of Aonghas "Mor" MacDonald? And this is a hypothesis that does not meet with any less favor than the suggestion that Margaret belonged to the family of Mar …

(We had recently been exploring primary sources for the MacDonalds of Islay, so if a deep dive is warranted, we do have a resource).