Sir Alexander Stewart of Darnley, Kt. - FMG citation no longer accurate

The ABOUT section cites https://fmg.ac/Projects/MedLands/SCOTLAND.htm#JohnIStewartDarnleydi...
Sir ALEXANDER Stewart of Darnley, son of Sir ALEXANDER Stewart of Darnley & his wife --- (-1404). m firstly --- Turnbull, sister of Sir JOHN Turnbull of Minto, daughter of ---. m secondly (1381) as her second husband, JANET Keith, widow of Sir DAVID Hamilton of Cadzow, daughter of Sir WILLIAM Keith of Galston.
'Sir Alexander & his first wife had six children:

1. Sir JOHN Stewart (-killed in battle near Orléans [1428/29]). Seigneur d'Aubigny. - see below.
2. Sir WILLIAM Stewart of Jedworth (-murdered 1402). - see below, Part E. STEWARTS of GARLIES, STEWARTS of MINTO, LORDS BLANTYRE.
3. ALEXANDER Stewart . Of Torbane and Galliston.
4. ROBERT Stewart .
5. JAMES Stewart .
6. JANET Stewart . m (1391) THOMAS de Somerville .

'Sir Alexander & his second wife had one child:

7. WILLIAM Stewart (-killed in battle Rouvroy 1429).

That cite now states, "Balfour Paul says that he married firstly the sister of John Turnbull of Minto, who (he says) was the mother of at least his six older children (no sources cited)[1623]. His suggestion is inconsistent with the sources cited below which name Janet Keith as the mother of Alexander’s oldest son John and suggest that she was also the mother of his daughter Janet."
He offers an idea where the Trumbull came from. " In a later passage, Balfour Paul records that “the crest of Sir John Stewart was a ‘bull’s head erased’, marking his descent maternally from the ancient Border family of Turnbull, who bore that cognizance”, . . . maybe Janet Keith was related to the Turnbull family through her mother (whose identity has not been traced).] "

Although Crawley calls Janet the 2nd wife, he has her the mother of the oldest children.