The Voyage of Bran: Appendix: IX. From Gilla Modutu's poe...
Cammán's daughter was Dub-Lacha,
[25] The beloved of Mongán, their offspring was good,
Colgo, Conall, that were folk of strength,
Cáintigern was his gentle mother.
Daughter of Demmán's son was Dub-Lacha
Of the white arms, without fault, of yore.'
[30] Cammán Dub, the daughter of Furudrán mac Bécce, of the royal race of the Ui Turtri, was the wife of Fiachna Dub mac Demmáin (LL: 140 a, 27).
Unless máthair mall may mean 'grandmother,' we must translate as I have done, and refer the a 'his' to Mongán.
[35] As to Dub-Lacha being called 'of the white arms,' cf. her by-name Láimhghel, p. 61, 10 above.