In Celtic mythology, Dea Matrona ('Divine Mother') was the goddess who gives her name to the river Marne (ancient MatrŏnaAncient authors referring to the river Marne as Matrona include Julius Caesar, Ammianus Marcellinus, Ausonius and Sidonius Apollinaris. ) in Gaul.
The Gaulish theonym Mātr-on-ā signifies 'Great Mother' and the goddess of the Marne has been interpreted to be a mother goddess.Cf.
See also Dea Nutrix, a Gallo-British mother goddess Aveta, another Gallic mother goddess
Sources
Beck, Jane (1970) "The White Lady of Great Britain and Ireland", in: Folklore 81:4. Loomis, Roger (1945) "Morgain La Fee and the Celtic goddesses", in: Speculum. 20:2. Meier, Bernhard (1998) Dictionary of Celtic Religion and Culture; Cyril Edwards, trans. Woodbridge: Boydell and Brewer.