Sigebert III, King of Austrasia - Sources?

@Sigebert III, King of Austrasia. Source "Dynasties of the World", John E Morby, Oxford Unversity Press, 1989, page 61.......This scholarly book has an entry in the list of the kings of "The Frankish Kingdom" that says:
639-656 St Sigebert III (son of Dagobert I: Austrasia 634)

Sigebert III, King of Austrasia is my 38th great grandfather.

Dagobert I, King of the Franks is my 35th great grandfather.

Sigebert III, King of Austrasia is my 39 th great uncle.

Dagobert I, King of the Franks is my 39 th great grandfather.

MedLands: King Dagobert I had one illegitimate child by Mistress (1):

1. SIGEBERT ([9 Oct 630/19 Jan 631]-1 Feb 656, bur Metz, basilique de Saint-Martin). Fredegar records the marriage of King Dagobert in the eighth year of his reign to "puella nomen Ragnetrudæ" and the birth of "filium…Sigybertum" in the same year[403]. The Gesta Dagoberti records the birth of his (unnamed) son to King Dagobert and Ragintrudis in the eighth year of his reign[404]. On the other hand, the Liber Historiæ Francorum names "Sighiberto et Chlodovecho" as the two sons of "Dagobertus rex…ex regina sua Nanthilde"[405], although this seems to be the only source which disagrees about the name of his mother. His father appointed him as SIGEBERT III King of the Franks in Austrasia in [Dec 633/Jan 634]. After his father's death, maior domus Pépin and the latter's son Grimoald, governed Austrasia in his name. Fredegar records that his forces were unable to repress the 639 rebellion of Radulf who declared himself king of an independent Thuringia[406]. He was canonised by the Catholic church in 1170. m CHIMNECHILDIS [Himnilde/Emnehilde], daughter of --- (-676 or after). The Passio Præiecti records the influence of "Imnichilde regine"[407]. The Gesta Episcopi Tullensis names "regem Dagobertum…genitricis ipsius Chimechildis reginæ" when recording a donation by the former[408]. "Childericus rex Francorum et Chinechildis regina…Bertuino comiti et Bertelando vicario" donated property "villam…Barisiacum…in pago Laudunensi" to "Amando episcopo" by charter dated to [1 Aug 661][409]. "Childericus rex Francorum, Bonifacio duci" donated property on the advice of "Emhilde regine" to the monastery of St Gregory in Vosges by charter dated to [660/62][410]. "Childericus rex Francorum" donated property on the request of "Amelrico, Bonefacio ducibus" and the advice of "Emnehildæ reginæ" by charter dated to [664/66][411]. "Childericus rex Francorum, Emnehildis et Bilihildis…reginæ…" confirmed the property of the monastery of Stablo and Malmedy by charter dated 6 Sep 667[412].

Mistress (1) is named above as Ragintrudis (see other discussion). So she wasn't a wife, but she was in the picture anyway.