N.N.

Speculated as a daughter of Tassilo II, duke of Bavaria.

Note from Justin Swanström, 3 March 2016:

English and German Wikipedia agree Tassilo II was a son of Theodo II and Folchaid. Salzburger Verbrüderungsbuch says he was unmarried. However, some other unspecified source says he was the husband of Imma, and father of Grimoald and of the Swanachild who married Charlemagne.

Notice that if he did marry an Imma there is no evidence I can find that she was a daughter of Gottfried of Alemannia, or that she was also the wife of Theodebert II, or that she was the mother of a woman who married Angier / Avernus of Prüm.