Story of Sage Narada turning into woman is found in the seventh Skanda of the Srimad Bhagavad Purana. During one of their travels, Sage Narada and Bhagavan Sri Krishna reached a stream. Sri Krishna warned Sage Narada to not to drink water from the stream. But the thirsty Sage ignored the advice and drank water from the stream.
The next moment Sage Narada turned into a woman and when she looked around, she did not see Sri Krishna.
She wandered through the forest and reached the ashrama of a Sage. The Sage had just opened his eyes after a long meditation.
He was impressed by the woman and married her.
In due course of time, she became the mother of sixty children.
One day her husband and all the sixty children died.
She was grief stricken and did not have the strength to cremate her husband and children.
Suddenly she felt an unusual hunger. She saw a mango atop a mango tree. She tried to pluck the fruit but she could not do it.
Due to the intense hunger, she placed the corpse on one top of another and plucked the mango fruit.
Suddenly a sage appeared there and scolded her for taking food without taking bath after the death of her husband and children.
She then jumped into the river holding the hand that held the mango above water.
The woman was transformed again into Sage Narada. But the hand that was held above water remained that of woman.
Sage Narada saw Sri Krishna standing nearby. Sri Krishna asked the sage to jump into the water and take a full dip.
This time Sage Narada dipped the hand that held the mango. He came out now holding veena in his hand.
Later Sri Krishna explained to Sage Narada that her husband was Kalapurusha and the sixty children were years.
The story symbolically states that unsatisfied desires and attachments results in rebirth.