Relationships between historical figures could have been simplified or even fabricated in the text to give the impression that succession remained within the same family….Precise chronology is also difficult to assess from the Sagas….The conclusion must be that the tight family network described in the Sagas is unlikely to be correct and that the relationships shown below should be treated with considerable caution. http://fmg.ac/Projects/MedLands/NORWEGIAN%20NOBILITY.htm
Snorre names "Emund, Astrid, Holmfrid" as the children of King Olof by his concubine Edla, specifying that Astrid was brought up in West Gautland in the house of Egil. Adam of Bremen records that the wife of Olav King of Norway was "rege Sueonum…filiam". The Historia Norwegie records that Olav married "soror Margarete" after his betrothal to the latter was terminated by her marriage to "rex Iarezlafus de Ruscia".