In an interview with Le Monde, the 61-year-old economist said the fight against corruption was at the root of the kidnap, with the abductors demanding her resignation on live television.
When asked what her failures and successes in the fight against corruption were, Okonjo-Iweala said: "Your answer would take a whole day.
"On my first experience as minister, I wrote a book, Reforming the Unreformable (ed) The MIT Press, 2012). For the second, it was really difficult. Nigeria subsidises fuel. About $ 6.7 billion that it costs, we found that 1.5 billion was fraudulent.
"One importer claimed that his boat was waging its oil while at the other end of the world, according to maritime classification society Lloyd's Register Marine.
"I told the president that we would stop paying. What happened? They kidnapped my mother, 83 years. During the first three days, their only demand was my resignation. I was supposed to go on television and announce my resignation.
"This was one of the worst moments of my life. Can you imagine what happens in your head if you have to be responsible for the death of your mother?
"I will not go into details, but you must understand that in a country like this... in the fight against corruption, we must be prepared to pay a personal price. My father asked me not to resign. The president asked me not to resign. At the end, everyone began looking for her, and the kidnappers released (her)."
Speaking to dwindling oil prices, Okonjo-Iweala said state governors did not allow Jonathan save for the rainy day, yet they are the ones complaining today.
"Some economists are very concerned for Nigeria, which could greatly suffer from the fall in oil prices. Others say the contrary, that its economy is strong enough to turn the corner.
"Both are right. But one thing saddens me. When I was finance minister the first time, the volatility of oil prices, and therefore state resources, cost at least three points of growth in the country.
"We then established a stabilisation mechanism and opened an account for the oil surplus, which posted up to $22 billion. In 2008, when prices fell from 148 to $ 38 a barrel, no one has heard of Nigeria because the country was able to tap into this fund. And that, I am very proud [of].
"When I returned to the department in 2011, there remained only $4 billion on this account while the price of oil was very high! I tried again to put money aside. The president agreed, but the governors did not accept.
"I suffered a lot of attacks from them and now that the country would really need this account, these same people accuse me of not having saved! If Nigeria had been more careful, we would not be here today. It hurts me. We have the mechanism, we had the experience, but we were prevented to act."
Okonjo-Iweala further spoke on her childhood and the hardship she experienced first-hand, during the Biafran war.
"I grew up in a village in southern Nigeria where I grew up to eight and a half years by my grandmother. My parents were scholarship students in Germany and did not have enough money to take me with them.
"I learned real life, fetching wood, water. At five, I could cook. This life has given me strength and a strong character. The other experience from my childhood is the Biafran war (1967-1970). My parents lost everything. I knew what it was to have nothing more."