Resigning then would have been seen as fleeing the "battlefield", the former chief minister says in her memoir.
"After the Nirbhaya incident, I was in a bind. My family, which had seen my distress throughout that period, urged me to step down as planned earlier, but I felt that such a move would be seen as running away from the battlefield," Ms Dikshit writes in 'Citizen Delhi: My Times, My Life'.
The recently published memoir takes readers through the lifelong journey of Delhi's longest serving chief minister.
Ms Dikshit also writes about her three terms in office, the changes she brought about in Delhi, the difficulties she faced and the electoral loss in 2013, among other things.
"Our party was defeated in unambiguous terms," she says about the defeat to AAP in 2013.
"I myself was defeated by a margin of over 25,000 votes, losing the prestigious New Delhi seat to Arvind Kejriwal of AAP, a party that many of us had underestimated."
According to her there were many who attributed the loss to public anger against the central government as the Delhi government was often identified with the UPA 2 simply because it was a Congress-led government.
"There was one more factor, I feel. A considerable chunk of voters who were casting their ballot for the first time, had not seen the Delhi of 15 years ago. To them a Delhi with regular power, flyovers and Metro rail, as well as several new universities, was their 'natural right' and therefore taken for granted. They could not be expected to feel ecstatic about it," she argues.
Ms Dikshit also says that following allegations of corruption in the 2010 Commonwealth Games and the 2G spectrum allocation as also Anna Hazare's anti-corruption movement, which was supported by an aggressive media, cracks started showing in the UPA government.
"During the debates and discussions in and outside Parliament, it was unable to communicate the simple fact that apart from a vigilance system, the country already had laws and regulations to tackle corruption," she says.
The Centre, she says, ended up looking "tentative" when "decisive political management" was needed.
"One image of senior Congress ministers going to the airport to receive Baba Ramdev, when the Anna camp had upped the ante, revealed the Centre's vulnerability before the entire nation," she says.
In 2011, Pranab Mukherjee and Kapil Sibal, then senior ministers at the Centre, met the yoga guru at the Delhi airport to dissuade him from going on a hunger strike. Their efforts, however, failed.
It was evident that the ground had started to shift for the Congress, particularly at the Centre, she writes in the book published by Bloomsbury.
"I also knew that the Centre's misfortunes would impact our standing in Delhi as well. Call it the effect of proximity, although to tell the truth, it was not always smooth going between our government and the Centre," she says.
Ms Dikshit goes on to say that she doubts if anyone remembered how her repeated demands for a greater statehood for Delhi fell on deaf ears, or how difficult it was for her government to push through the reform of splitting the MCD into smaller and more manageable units.
"Party members rose against the proposed move; among them were many who had supporters at the Centre. It was only after the intervention of the High Command that this measure was approved. Instead of the original plan of MCD being divided into five units, however, it was now divided into units in charge of North, East and South Delhi, respectively," she says.
On her plans to step down, she writes that as the winter of 2012 approached, she was overcome with fatigue and bouts of breathlessness.
"I felt it was time for me to step away from electoral politics. My family told me in no uncertain terms that I needed to put health concerns before everything else. My decision to resign was almost certain. Moreover, with a year to go for the assembly election, the party had enough time to find an alternative," she says.
But as she slowly recovered her strength and prepared to inform the high command of her decision to step down, Delhi and India were shaken to their core on December 16, 2012, as the young woman -- later named Nirbhaya by the media -- was brutally raped by a gang of men in a moving bus.
The incident prompted Ms Dikshit to stay on.