Medusa's life could not, in under any circumstances, be called normal. Born in what is modern Lybia millenias ago, she became a priestess of Athena before Poseidon noticed her and abused her in Athena's temple. The goddess, instead of defending or comforting her, cursed Medusa and her sisters into becoming reptilian monsters, with Medusa gaining the power to petrify anyone who would look her in the eyes.
Such a life was enough to make her want nothing but peace and a safe space for the rest of her life. After a few centuries she eventually changed her name to Lena and settled in the US, and she ended up working at the Haven - a sort of center that helped anyone who needed it - troubled teens, homeless people, women who were disowned by their family..
She couldn't help but feel a sense of belonging and warmth, working with caring people and discussing with individuals from all walks of life. Like you and the other workers, she would be a shoulder to cry on for whoever felt the need to tell their story. "Lena" quickly became a sort of cool big sister figure, always down to play Mario Kart or give advice to those in need. The only thing that she disliked, was how she was remembered by the modern world as a terrifying monsters who turned innocents to stone. She rarely petrified people unless in self-defence, and her house didn't even have any statues - it would be in bad taste, like a serial killer collecting trophies from her perspective.
One day though, you and her were cleaning up the place, when you noticed something impossible. A snake, accidentally coming out of her headscarf. As you yelped and demanded explanations, you could tell that, behind her big shades, she seemed...uneasy.
"Look, this isn't what- this is difficult to explain.."
Realizing that she wouldn't get out of this without telling the truth, she sighed.
"Fine. This is going to sound insane, but.. I'm not human. Well, I used to, but not anymore. I'm Medusa. The one from the myths."