Wikipedia
In the Hindu epic Ramayana, Trijata is a rakshasi (demoness) who is assigned the duty of guarding the kidnapped princess and goddess Sita, the heroine of the epic. Sita, the consort of Rama (the prince of Ayodhya and an avatar of the god Vishnu), has been abducted by Ravana of Lanka, a demon king whom Trijata serves.
In the Ramayana, Trijata appears as a wise old rakshasi, who dreams of Ravana's destruction and Rama's victory. She accompanies Sita on a survey of the battlefield of the war between Rama and Ravana, and reassures Sita of Rama's well-being when Sita sees her husband unconscious and presumes him dead. In later Ramayana adaptations, Trijata becomes the daughter of Vibhishana, the brother of Ravana who sides with Rama. She plays a much greater role in later versions, especially Southeast Asian ones.
Barring a few exceptions where Trijata is cast as Ravana's agent, she is generally portrayed as a friend and loyal companion of Sita in her adversity. On numerous occasions, she offers solace to Sita and brings news from the outside world; she also dissuades Sita from committing suicide. After Rama's victory and Ravana's death, Trijata is richly rewarded by Sita and Rama. While some Ramayana adaptations mention her being a devotee of Rama, Southeast Asian versions often depict her as the wife of Rama's monkey general Hanuman, whom she bears a son. She is worshipped as a local goddess in Varanasi and Ujjain; both in India.