Must Read: Aisha is not the mother of the believers (Umm al-Momineen) - Detailed Analysis:

http://ashqayaan.blogspot.in/2014/11/aisha-is-not-mother-of-believers.html

Narration 1 - Her sin is massive (Azeem):

حين جاء قوم من أهل البصرة إلى الصادق (عليه السلام) وسألوه ... قالوا: فإن طلحة والزبير صنعا ما صنعا، فما حال عائشة؟

قال: عائشة كبير جرمها، عظيم إثمها، ما أهرقت محجمة من دم إلا وإثم ذلك في عنقها وعنق صاحبيها

When a group came from Basrah to Imam Sadiq (as) and asked him about the War of Imam Ali (as) against Talha, Zubair and A'isha. 

They said, "Talha and Zubair did what-ever they did, but what is the position of A'isha"?

Imam (as) said, "Aisha's crime is huge and her sin is massive (Azeem). And no blood was shed but that its sin is upon her neck and the neck of her 2 companions (Talha and Zubair).

(Part of a lengthy narration)

[Source: Dalaail al-Imamah - Shaikh Tabari (shia), Pg. 267]

Narration 2 - Imam al-Qaim (atfs) on A'isha being divorced by Imam Ali (as):

فقلت له : مولانا وابن مولانا ! إنا روينا عنكم أن رسول الله صلى الله عليه واله جعل طلاق نسائه بيد أميرالمؤمنين عليه السلام حتى أرسل يوم الجمل إلى عائشة أنك قد أرهجت على الاسلام وأهله بفتنتك ، وأوردت بنيك حياض الهلاك بجهلك ، فان كففت عني غربك وإلا طلقتك 

فأخبرني ياابن مولاي عن معنى الطلاق الذي فوض رسول الله صلى الله عليه واله حكمه إلى أميرالمؤمنين

قال : إن الله تبارك وتعالى عظم شأن نساء النبي صلى الله عليه واله فخصهن بشرف الامهات ، فقل رسول الله صلى الله عليه واله : يا أبا الحسن إن هذا الشرف باق لهن مادمن لله على الطاعة ، فأيتهن عصت الله بعدي بالخروج عليك ، فأطلق لها في الازواج وأسقطها من شرف امومة المؤمنين

Following question was asked to Imam Al Qaim (atfs) .. (only relevant part of a lengthy narration quoted here)

I asked: "O our master and master’s son, it is narrated to us that the Holy Prophet (saww) had given Amirul Momineen (as) the right to divorce his wives. Therefore on the day of Jamal, he sent message to Ayesha that she had wreaked havoc with Islam and Muslims (and taken wrong advantage of her position). That she has in an ignorant way condemned her children to perdition. 'Thus if you do not refrain from your act I will divorce you.'

Tell me, my master, that what is the meaning of divorce here? That the Messenger of Allah (saww) left it at the discretion of Amirul Momineen (as)?"

Imam Al Qaim (atfs) replied: "The Almighty Allah, hallowed be His name, gave an exalted status to the wives of the Prophet and gave them the honor of being the mothers of the faithful. Thus the Messenger of Allah (saww) told Amirul Momineen (as): O Abal Hasan, this status is valid for them till they remain in the obedience of the Almighty Allah. So whoever of them disobeys Allah and after me, comes out in armed confrontation against you, remove her from my wifehood and take away her status of motherhood of faithful."

[Source: Kamal al-Deen - Shaikh Sadooq, Vol. 2, Pg. 459]

Hadith 3:

عَنْ يُوسُفَ بْنِ كُلَيْبٍ اَلْمَسْعُودِيِّ قَالَ حَدَّثَنَا أَبُو مَالِكٍ عَنْ عَبْدِ اَللَّهِ بْنِ عَطَاءٍ عَنْ أَبِي جَعْفَرٍ مُحَمَّدِ بْنِ عَلِيٍّ عَلَيْهِ اَلسَّلاَمُ قَالَ: قَالَ عَلِيٌّ صَلَوَاتُ اَللَّهِ عَلَيْهِ  لُعِنَ  أَهْلُ  اَلْجَمَلِ فَقَالَ رَجُلٌ يَا أَمِيرَ اَلْمُؤْمِنِينَ إِلاَّ مَنْ كَانَ مِنْهُمْ مُؤْمِناً فَقَالَ عَلَيْهِ اَلسَّلاَمُ وَيْلَكَ مَا كَانَ فِيهِمْ مُؤْمِنٌ

Narrated that Abu Jafar Imam Baqir (عليه السلام) said, that Imam Ali (عليه السلام) said,

"The people of Jamal (i.e. those who participated in the battle of camel under the leadership of Ayesha) were cursed."

So a person said, "O Amir al-Momineen (عليه السلام),  except for the believers from amongst them."

So Imam Ali (عليه السلام) replied, "Woe to you, there were no believers among them."

[Source: al-Kafiah fee ibtaal Tawbat al-Khatiyah - Shaikh Mufeed, Pg. 41, Hadith. 48]