The popular legend behind Jamai Shasthi says that once upon a time a family lived in a small town. The youngest daughter-in-law of that family was a greedy woman. She used to consume most of the eatables and blame it on the cat that regularly came to their home.
The cat complained about the injustice to Goddess Shasthi. Later when the same daughter-in-law gave birth to seven sons and a daughter all her children were stolen. She was shattered and depressed. She went to jungle with her broken heart. On seeing her crying Goddess Shasthi felt pity on her and appeared before her as an old lady and asked the reason for her remorse.
The young woman narrated her sorrow, Goddess Shasthi reminded her of her past wrongdoings. She apologized for her behavior and asked for mercy. Then guised old woman asked her to perform some social rituals to get back the children.
Thus from that day onwards women folks takes the advantage of praying and performing puja to the Goddess Shasthi for their children on the sixth day of bright phase of Jyestha. Gradually this day developed as Jamai Shasthi.