There is no single 'Sunni understanding of history'. Islamic history and its vast sources are too vast and multi-vocal for it to have one understanding on this matter. The Sunnis themselves have multiple views on the subjects even among the theological schools of the 'asharis and mu'tazila (some of the theological schools among Sunnis). However the predominant view is that she died a natural death. However the Sunni leaning historical tradition such as History of al-Tabari and the Ansab al-Ashraf of al-Baladhuri do indicate that something violent or potentially violent occurred at the hosue of Fatima (as) following the death of the Prophet. For instane al-Tabari relates that the end of the his life, the first caliph said: " I wish I did not throw open/or unveil the house of Fatima - lam akshif manzil fatima, however they ( Ali, Fatima and those in the home) had locked it down with hostile intent - ghalaquhu 'ala al-harb. So clearly something violent or potentially violent occurred as per this narration found in al-Tabaris's history under the section dealing with the final words of the 1st caliph at his death. That being said, the Sunni historical tradition for the most part do not describe her as being injured or killed as a result of that incident. However there were others such as al-Nizam, the famous Mu'atazlite theologian (who would also be considered to belong broadly to the Sunni school or at least non-Shia in a formal sense) who describes her as being injured and dying from this and he was in-fact blamed for this and condemned by later scholars for holding such a view. Thus it was a view that existed in the Muslim community.