Sol was born in the great valleys of the river Anduin among her kin, but because of her stunted growth her early childhood was not as idyllic as one might like. Always the runt, she was an easy target for her siblings and cousins, and children can be so very cruel when left unsupervised. It is not a time Sol chooses to speak of often.
What she does remember fondly though is the adults' tales, particularly the one her aging grandsire used to tell about his encounter with the company of Thorin Oakenshield, and how he'd fought on the slopes of Erebor. She didn't listen to many of his other teachings, but whenever he spoke of dwarves or tearing through goblin ranks he was given her full attention.

When she was nearing her eighth year, Sol had taken to wandering far from her sheltered home to be free from her tormentors, often gone for days at a time until one of the adults came to find her and drag her back. It was during one of these long walks she picked up scents completely foreign to her and followed them to their source, a group of dwarven merchants on their way up through the passes of the Misty Mountains.
For weeks she stalked them, mistaken for an overly curious, and probably very hungry, young bear and chased off more than once by the dwarves. There was even a discussion about turning her into a nice warm pelt. Only after Sol had proven her worth during a goblin ambush did they let her near their camp without throwing axes at her, and from there mutual trust grew. Months later when they finally reached the Blue Mountains, the leader of the little company, Volheim Stonehammer, had a fatherly fondness for the savage girl and started caring for her as if she was his own child, albeit a beardless one. 

While met with wariness and scepticism at first, Sol had her clan watching over her, foremost was her adoptive father and his brother Groheim, both taking it upon themselves to educate and train the girl, teaching her as much as they could from reading, writing, and counting, to working a forge and fighting as a berserker. For rage was never something Sol had any difficulty tapping into, easily making up for what she might lack in size compared to the rest of her kin in sheer ferocity, but in those early years controlling it was a different matter entirely. Under her uncle's guidance she became a skilled and mighty warrior, and started using her talents to help protect the dwarves of the Blue Mountains and their outposts, slowly earning their trust and respect over the long years, and they even took to calling her 'Dvargbjorn', dwarf-bear in her native northern tongue, as a gesture of kinship. 

It was wanderlust more than anything else that made her decide to take to the road and start travelling the length and breadth of Middle-Earth, hiring herself out as a caravan guard and occasional mercenary in order to see the world. She will not take just any job though, shunning anything criminal or what she might deem dishonourable, something that seems to confuse people in the towns and villages of Men due to her otherwise so savage nature. 

Sol lives by her own set of beliefs and rules for the most part, though she tries to remain respectful of local laws and customs. Unlike the rest of her kin, she does not abstain from eating the meat of animals, rather seeing herself as an apex predator and relishing in the hunt. She does however have certain reverence for nature, more at home in the wilds than anywhere else.