About Poppa of Bayeux
Poppa de Valois de Bayeux, married to Rollo de Normandie.

Poppa was not a duchess, countess or princess, and her husband Rollo was not a duke but was referred to as "comes", a count.

It is not clear which of Berengar's wives was her mother.

NOTE: Keats-Rohan suggests that "the origin of Rollo's wife Poppa should be sought among the German Popponides, and that, specifically, that we see her as granddaughter of Henry of Thuringia, marquis of Neustria at his death in 878 and ancestor, through his daughter, of the Ottonians." [KSB Keat-Rohan, "Poppa 'of Bayeux' and her family," The American Genealogist 72 , pp. 187-204]

Medieval Lands
There is a disconnect between Poppa married to Rollo and Poppa married to Balso - from a timeline point of view there’s no way these can be the same woman. Hopefully the historians can help us.


FMG.ac
Gange-Hrolf married: m [secondly] POPPA, daughter of BERENGAR Comte de Bayeux & his wife ---.

Guillaume of Jumièges records that Rollo took "Popa, fille de Bérenger, homme illustre" when he captured Bayeux and "s´unit avec elle, à la manière des Danois"[31]. According to Orderic Vitalis, Rollo "stormed and captured Bayeux, slew its count Berengar and took to wife his daughter Poppa"[32]. In another passage, the same source records that Rollo besieged Paris, captured Bayeux, killed "Berengarium comitem" and married his daughter Popa, in 886[33], although this date appears early in light of the likely birth date range of the couple's son Guillaume. The Chronico Rotomagensis records that "mortua a Gisla, accepit Rollo propriam uxorem filiam comitis Silvanectensis Widonis"[34]. Robert of Torigny combines the information, recording that "Rollo dux Northmannorum" married "Popam prius repudiatam uxorem…filiam…Berengarii comitis Baiocensis neptem vero Widonis comitis Silvanectensis"[35]. The Historia Norwegie records that, after capturing Rouen, "Rodulfus" married the daughter of its deceased count by whom he was father of "Willelmum…Longosped"[36]. Guillaume de Jumièges records that "le comte Bernard" welcomed "son neveu Richard" at Senlis after his escape from captivity[37], although in another passage he describes how Rollo captured Bayeux and took "une très-noble jeune fille Popa, fille de Bérenger" in the town, marrying her "à la manière des Danois"[38], in a later passage adding that Rollo married Poppa, whom he had previously repudiated, a second time after the death of his wife[39]. It would be possible to reconcile the different versions if Comte Bernard's mother was married twice, her first husband being Bérenger Comte de Bayeux.

From http://fmg.ac/Projects/MedLands/FRANKISH%20NOBILITY.htm

BERENGER . Comte de Bayeux. According to Orderic Vitalis, Rollo "stormed and captured Bayeux, slew its count Berengar and took to wife his daughter Poppa"[770]. In another passage, the same source records that Rollo besieged Paris, captured Bayeux, killed "Berengarium comitem" and married his daughter Popa, in 886[771], although this date appears early in light of the likely birth date range of the couple's son Guillaume. m [as her first husband] --- [du Vexin], daughter of PEPIN [Carolingian] & his wife ---. Berengar & his wife had one child:

a) POPPA . According to Orderic Vitalis, Rollo "stormed and captured Bayeux, slew its count Berengar and took to wife his daughter Poppa"[772]. In another passage, the same source records that Rollo besieged Paris, captured Bayeux, killed "Berengarium comitem" and married his daughter Popa, in 886[773], although this date appears early in light of the likely birth date range of the couple's son Guillaume. The Chronico Rotomagensis records that "mortua a Gisla, accepit Rollo propriam uxorem filiam comitis Silvanectensis Widonis"[774]. Robert of Torigny combines the information, recording that "Rollo dux Northmannorum" married "Popam prius repudiatam uxorem…filiam…Berengarii comitis Baiocensis neptem vero Widonis comitis Silvanectensis"[775]. Guillaume de Jumièges records that "le comte Bernard" welcomed "son neveu Richard" at Senlis after his escape from captivity[776], although in another passage he describes how Rollo captured Bayeux and took "une très-noble jeune fille Popa, fille de Bérenger" in the town, marrying her "à la manière des Danois"[777], in a later passage adding that Rollo married Poppa, whom he had previously repudiated, a second time after the death of his wife[778]. It would be possible to reconcile the different versions if Comte Bernard's mother was married twice, her first husband being Bérenger Comte de Bayeux.

m as his second wife, ROLLO, later known as ROBERT I Comte [de Normandie], son of [RAGNVALD "the Wise" Jarl of Möre in Norway & his wife Ragnhild] .