Nesteril was the second born child to Echeth and Aegassion after her brother Curain, and before her younger sister Aradeth. They grew up in Esteldin, where they trained from the moment they were old enough to. While Curain favored the sword, Nessa took after her mother and grew to be quite good at archery. She's a master marksman now, as well as a sufficient Healer. Her parents and her younger sister moved when they were still young, but Curain and Nessa remained in Esteldin.

The pair of siblings traveled across Eriador until they were called to help with Reviadir's cause, and they joined up with the other rangers that came to help. Nessa took a particular liking to Artemieth and considered her a good friend, but the others did not much care of her brother, and so they did not care for her. As such, and though she was a valued group member and took care of everyone's healing needs and looked after everyone, she did not much care for them either. Curain caused a lot of discourse wherever he went, and Nessa was expected to pick up after him, even when she didn't agree with her brother.

Eventually, Nesteril and Curain both moved on from the group when their work was done. She had fallen in love with Turchon, only to be completely discarded afterwards, and Nessa was heartbroken. Her brother and her continued to travel, though now on their own. They traveled to Gondor to help fight at Minas Tirith and that is where Nesteril lost her brother. She is not sure if he is dead or if he made it out alive, but she does not know where he is. She spent ages searching for him, but she decided to return to Esteldin, because she figured that is where he would go to look for her as well.

She now resides in the North Downs, doing what she can there and lending her help as a Healer.