Somebody seems to have identified her with the unnamed mistress of Alexander II who bore him a daughter Marjory who became the second wife of Alan Durward. But since Isabel herself was his *first* wife (her second husband), this identification is extremely suspect to say the least.
Isabel was married to 1) Thomas of Galloway, 2) Alan Durward.
Alexander II was married to 1) Joan of England (daughter of Bad King John), 2) Marie de Coucy.
None of the above marriages is recorded as producing any daughter Devorguilla or Dernell or any such name.
The name "Devorguilla" occurs twice in the Galloway line, once as *sister* to Thomas of Galloway, once as his *niece*. Neither one married into the Hoos.
We do *not* know the names of the two younger daughters of Alan Durward, nor whom they married, nor what became of them. Possibly one of *them* married a Hoo and started the whole legend.
There is a record in the Feet of Fines (CP 25/1/9/34, number 3) of a William, son of Alexander de Hoo, who won a court case in 1292 against one Richard de Culworth involving Richard's fees and subfealties - but that's all we know of "Alexander de Hoo". Or for that matter William. https://www.medievalgenealogy.org.uk/fines/abstracts/CP_25_1_9_34.s...
