I feel that anyone who looks into the recordings of the Islamic historians and also the narrations with regards to the bitter events that occurred following the demise of the Holy Prophet will not disagree on this matter. We will now look at what has been written on this matter:
1) The late Kulayni (2) narrates from an accepted narration from Imam Kadhim (as) in the chapter called ‘The birth of Hazrate Fatemeh (sa)’ the second narration states as such:“Surely Fatemah (sa) Seddigheh is a martyr.”
And the late Majlisi in Miraat Al-Uqool after mentioning this statement as being true and correct, in the explanation of Usool Kaafi wrote the following:
“Without doubt this news is a reason in itself that Hazrate Fatemah (sa) is a martyr in the path of the truth; and this news has been discovered time and time again and the cause of this is that after the usurpation of the caliphate and the seizing of the power through the event of Saghifeh, Gonfoz pushed the door of the house of Hazrate Fatemah (sa) with such force into the stomach of the great lady that her side was broken and caused her to lose the child she was carrying at the time that the Prophet had named Mohsen and then became ill and through which she died as a martyr.”
Then the late Majlisi narrates from Shia and Sunni scholars who have supported this event. In particular one narration which is lengthy from Soleem ibn Ghais Helali, a part of which is as follows:
“Fatemeh (sa) is a martyr in the way of Allah and the cause for it is that following the usurpation of the caliphate and the happenings of Saghifeh, Gonfoz the slave of Omar hit Fatemeh (sa) and then pushed her with such force, and this crime resulted in the ribs of Fatemah (sa) being broken and due to the severity of her injuries it soon lead to her martyrdom.”
2. More so mentionable than that narration is this long narration from the late Sadooq, from Ibn Abbas narrated from the Holy Prophet (saw), a part of which is as follows:
“... and when I see my Fatemah, I remember that violation and transgression that will take place against her after my demise, as though I can see the sad day when the enemies enter her home, disrespect her, usurp her rights and inheritance, and break her ribs and murder her child that has not yet been born! And she shouts out for assistance ‘Oh Mohammad!’ but no one comes to her aid or answers her helpless call! And she seeks protection from the violation and oppression while no one offers her refuge and no one assists her.” 
3. Amongst the endless narrations, there is the ‘Ziyarat’ of Hazrate Fatemah (sa) that the late Sayyed Ibn Tavoos in his book Iqbalul Aamaal has mentioned, a part of which is as follows:
Until you say:
“And send salutations upon Fatemah Batool, that same chaste lady of purity and and virtue; that same lady whose rights were usurped; and whose paternal inheritance was kept from her and whose ribs were broken by the oppressors’ aggression against her...” 
However, countless narrations also mention the setting alight of the door to Hazrate Fatemah’s (sa) house, her excellency being pressed with great force between the door and the wall of her house, and the miscarriage of her unborn child caused by the breaking of her ribs and injuries to her side.
 – Usool Kafi, Volume 5, Page 315
 – Sadooq, Mutawafi 381 AH, Amaali, Volume 24, Pages 99-100
 – Iqbal, Page 152.
Yes, the narrations mention this bitter truth. The bringing of logs so that the house of Hazrate Fatemah (sa) could be set on fire while a group of people and lovers of the Ahlulbayt (as) had sought for protection there, and this is famous and well known amongst the followers of the path of the Ahlulbayt (as) - as they write:
“Of course we have brought this narration from the Sunni scholars in particular ‘Balaazari’ and there are numerous narrations from the Shia scholars too in which there is no conflict of opinion regarding them on this matter.”
Masoudi, the author of the famous book Morooj Al-Dhahab in another book of his called Ithbaat Al-Wasiyyah has written the following: So the supporters of the Caliph went towards the house of Amir Al-Mo’mineen (as) and attacked the house and set the door on fire and then forcefully brought the Hazrat out of his house and the leader of the women of heaven, Hazrate Fatemah (sa) was pressed brutally between the door and the wall causing her to miscarry her unborn child Mohsen. 
Summarizers Note: Abbas, the uncle of the Prophet asked Amir Al-Mo’mineen, “Why did Omar deduct a part of all his worker’s wages as tax but did not deduct anything from the wages of Gonfoz and paid him fully?” His Excellency looked around him and then while his eyes were filled with tears that fell he answered:
“The full payment to Gonfoz was because his appreciation of him and because of the violent lashes he had inflicted upon the body of Hazrate Fatemah (sa), that had been such that when the dear daughter of the Prophet of the Earth said farewell, the effect of those violent lashes were evident on her upper arms as though they were armbands.” 
The violation against the rights of the daughter of the Prophet Hazrate Fatemah Zahra (sa) which took place is an event that has been proven as it has been recorded in many authentic sources. The only ones to deny this are those who are ignorant or refusing the truth. The violation against the rights of the daughter of the Prophet Hazrate Fatemah Zahra (sa) which took place is an event that has been proven as it has been recorded in many authentic sources. The only ones to deny this are those who are ignorant or refusing the truth.
The violation and transgression of the rights of the daughter of the Prophet, Hazrate Fatemah Zahra (sa), from the attack on her house up to the usurpation of her property and the breaking of her ribs, and injuries to this great lady all in all were due to the fact that she sought justice, stood up against the oppressors, and defended the rights of the innocent Imam (as), and certain parts of her radiant speech refers to and brings this truth to light. Upon saying this, how can this jihad and great defence by the Great lady of Islam Hazrate Fatemeh (sa) be separate to the views of the heavenly vicegerency of Amir Al-Mo’mineen (as)?
 – Ithbaat Al-Wasiyyah, Page 122
 - The book of Soleem ibn Ghais, p134
Therefore, how can this not be linked to our beliefs and instead be regarded as just a sorrowful story in history?!
The truths surrounding this great catastrophe are so evident that even a person considering them with a bit of conscience and sense of humanity will not be able to reject this painful tragedy. The collection of narrations and the history regarding this painful tragedy has been proven by the greatest of Scholars.