Marillen was born in Valinor in Years of the Trees. From her youth, she was very curious and loves learning new things, elves says, that she has sunfire inside of her which made her want do "go on" or be active. She choose to be a healer, even people says her, that she will do not have any work. Her healing skills were described as she is able to:"iginite will to life and power of spirit" which help recover more quickly. Este discovered her talent and started to teach her. Marillen later became one of the greates healers of First age.