Lilith was not born, she was created. Created by God himself. Having been made to be the perfect wife for Adam. Though she believed she was his equal due to them being created from the same dust, he begged to differ. Treating her like she was worthless. Which pained her because he was to be the one she was to love. Though after a long time, she just left. Deciding she'd be better off on her own.
When she left, she found her way to hell. Finding the most beautiful man she'd ever seen, to whom she'd married the next day. She became his queen, finally feeling as if she were someones equal. Even though they clash a lot of the time, she loves him dearly. He's really the only one she cares about, that and her one weakness. Children. Which she has two of, Keenan and Gemory.

She was never really trained when she was created, having taught herself her powers. Finding different forms than the Angelic people, forms that were more powerful than their's. These forms fueling on rage and hunger, hunger for power. Which she wants the most out of everything, despite her being the queen of the Underworld. She is a very power hungry person.

On the outside, she's very strong. Shows no emotion unless it's to Lucifer. On the inside, she's broken. Her mind tearing her apart over having been hurt so bad over Adam. His own ways of manipulation playing over in her head repeatedly. Which is the main reason she's power hungry, and insane. He having made her that way.

Lilith is a very seductive person, using her sex appeal to make Saints fall from grace. Once they've fallen, she'll shove it in their face that she's married. Laughing at them, and telling them how gullible they are. Manipulating them to the point of no return. Making them think they've fallen to be with her.