Ruodhaid (775–810), Abbess of Faremoutiers [1] ROTHILDIS [Rouhaut] ([784]-24 Mar 852). Abbess at Faremoutiers from before Oct 840[157]. Her parentage is proved by the necrology of the abbey of Saint-Germain-des-Prés which records the death "XI Kal Apr" of "Rothildis abbatisse et monache filia regis magni Karoli"[158]. The necrology of the abbey of Saint-Denis records the death "XI Kal Mar" of "Rotildis abbatissa"[159]. [2] CHROTHAIS [Rotaïde] ([784]-after 800, maybe after 814). "Ruodhaidem" is named daughter of King Charles and an unnamed concubine by Einhard[155]. Theodulf's poem Ad Carolum Rege names (in order) "Berta…Chrodtrudh…Gisla…Rothaidh…Hiltrudh, Tetdrada" as daughters of the king[156]. :[3]
French and German Wikipedias put the Abbess's death at 852; the French one refers to interesting article about her and calls her "Rothilde". That probably does not indicate that the abbess was a different daughter of Charlemagne, because both of those say she was the daughter of Madelgard(e).
Medieval Lands says she became "Abbess at Faremoutiers from before Oct 840" and died 24 March 852, and says "Her parentage is proved by the necrology of the abbey of Saint-Germain-des-Prés ..."
Ruothild at Genealogics, citing as source "Caroli Magni Progenies, Neustadt an der Aisch, 1977 , Rösch, Siegfried, Reference: 64", says she died 24 March 852