I've been thinking about this for awhile now, this would explain why Freyla has been in captivity for so long. 

Freyla is actually a princess?

Being the only daughter to the king and queen of whichever kingdom in Middle Earth, having been kidnapped as an infant.

The man who kidnapped Freyla had worked for the king, eventually betraying the king and queen by murdering them both. Freyla only an infant, unaware of what is happening around her. She is soon taken from her cradle and her home. 

This man planned to sell Freyla, though the risk of getting caught was too high. So instead he moves far from the kingdom keeping the kidnapped princess hidden. He soon locks Freyla in his cellar, where Freyla grows up. Though she lives a rather unhappy, fearful life. Enduring her kidnappers abuse, his anger for having lost his fortune because of her. Along with having to hidgo into hiding leads him to take his anger out on Freyla.

Freyla is unaware of who she truly is, not knowing the true reason behind his cruelty. Freyla so desperately wants to escape, to be out in the world. Though her captor knows her freedom would likely lead to his death, so he does his best to keep her from escaping. Either let her die within his cellar, or beat her enough until she's dead. 

However the unexpected happens, Freyla manages to escape. Wounding her captor, giving her time to run.  Which eventually leads Freyla to the elves, where she finally has her freedom. It's possible that the elves can learn, or have an assumption of who she truly is. When given the chance to reclaim her title as princess, Freyla refuses. Freyla also refuses to leave the elves, having grown fond of them and is even in love with an elf.

Freyla is a returning character, I made her maybe a year ago. I abandoned the account, only because I wasn't happy with her character development. I didn't have a story for her, bio is easily changeable to better fit stories.

Freyla is a young human girl (Age can be determined during discussion) living in middle earth, having been kidnapped as an infant. Freyla lived with her captor her entire life, never allowing her to go outside. He was abusive, treating Freyla horribly the older she got. A few months after Freyla turned fourteen, Freyla managed to escape. (Age can be changed if others aren't comfortable with that age.)

while fighting with her captor, smashing a stone into his head while attacking her. This gave Freyla time to escape, running from his home and into the forest. Having been in captivity for so many years, Freyla didn't know much if not anything from the outside world. Freyla unknowing of Elves, Dwarfs, Hobbits and any other creature man or not that lived in Middle Earth.

Freyla ran through the woods, barefoot, dirty with tattered clothes, malnourished and very disheveled. Desperate to get away, desperate to live

Freyla was followed, her captor chasing after her.  It wasn't until Freyla had entered the elves realm,  she had been shot in the back twice with arrows. Freyla refused to give up,  struggling to continue to escape. (Either by the elves, or by her captor)
Freyla was soon found and was given aid from the elves, imprisoning the man.

Having been taken in by the elves, they quickly tended to her wounds. They were able to heal her physically, though mentally was another story. 
Freyla was allowed to live among the elves, later falling in love and marrying an elf.