Sybil Biornsson

Siward of Northumbria, Earl of Bamburgh might have had a daughter called Sibyl or Sybil.

This one was NOT married to Donnchad, King of Scotland - he was married to Suthen (Sibylla) who was Siward's cousin, and NOT his daughter.

This profile might end up deleted or moved later, if we don't find out whether Siward really had a daughter.