As per ancient legend, Vedavati is an incarnation of Ma Bhudevi, and after her death, she has taken birth as Sita Devi, the pious and chaste consort of Lord Rama, and she is a worshipful mother goddess.
Vedavati is the daughter of sage Kushadhvaja, and the granddaughter of Brihaspati, the holy Deva Guru. Since her father was an expert in Vedas, he named his daughter as Vedavati, and she was brought up by her father in a well-versed manner.She was a staunch devotee of Lord Vishnu, and she prefers him as her consort. Due to that she rejected all the marriage proposals of the kings, and the demigods, and hence, a king killed her parents during an Amavasya.
Vedavati still lived in the ashram of her parents, and began to mediate on Lord Vishnu, in order to make him as her husband.She lived a saintly life, used to wear the Holy JapaMala with a matted hair and appeared like a pious Rishi. She looked very beautiful, similar to the full moon.Once while Ravana, was passing that way through his divine Pushpaka Vimana, he found Ma Vedavati sitting in the meditation posture. He was very much attracted with her beauty, and he was willing to marry her. But she rejected his proposal, and kept meditating on Lord Vishnu.
As a result, Ravana tried to molest her. But she cursed, and told to him, that she would be born again in the world, and she would be the main cause of his destruction, and then she created fire through her spiritual powers, and in front of him, she fell down in the fire, and died.
Similarly, she took birth as Sita, and she was adopted by her foster father Janaka, and lived in his Videha Kingdom. After she attained teenage, Lord Rama broke the divine bow Pinaka, and married Sita. During their stay at the forest, Ma Sita was kidnapped by Ravana, and after a few months, with the help of Lord Hanuman and Sugriva, Lord Rama fought with Ravana, killed him in the battle, and brought back Ma Sita to his Ayodhya Kingdom.