Godgifu - The mother of Siward's son, Osbeorn?

If so, then perhaps we can add the much discussed (Suthen; Sybilla) sister of Siward; (wife of Duncan) as a child of this woman too - and presume that Siward is an old man when he has his second family.
I'm not actually sure if this would fix the present age-range impossibility of a daughter (not a sister) of Siward marrying Duncan - so it's just a thought that I'm recording to come back to.

On which thought - perhaps Osbeorn, Siward's son (presuming he did exist) - is actually an adult man when he dies in battle against Macbeth & his father is allegedly comforted by the fact that he was wounded in the front not the back).

This would make Siward much older when he dies of dysentry a year later (allegedly refusing to die, lying down - but insisting on having his boots on when he dies :-).
Which, to my mind, is a bit more commensurate with a man who is able to impress Cnut and hold the heavily contested area of southern Northumbria from before 1030 (possibly as early as 1023) - Not something a young man would have found so easy to do, I think - even if he was a huge 'bear' of a man in stature.

Oh I didn't highlight the profile of Sybil Biornsson - daughter, sister, cousin of Siward, for whom we presently have a 'duplicate' place-holder profile: Suthen Sibylla of Northumbria as the wife of Duncan I, King of Scots.