Rosalie Carstairs, a thin girl with silver streaks in her hair and a broken mind. Though as broken as she was, when she met William Herondale, she finally felt like she was being pieced back together.

Let me take you back a few years ago…

Rosalie was panting, terrified. She was 16 and had finally escaped – the girl banged on the door to the London Institute with trembling hands.
A man answered, "A damsel in distress? How intriguing" This man, was named William Herondale, and he watched the stranger with confused eyes.
A silver hair man stepped down the stairs with his fiancée, and froze, seeing the figure "Rose" he whispered, "Rosalie"
"I'm home"
They embraced tightly and soon informed the others on what had happened between them.

A couple of months later, Will found that the only way he could get over his best friends engagement to the woman he loved, was to distract himself with another girl, a girl which happened to be Rosalie. And she fell in love with him.

But now, things had changed, as she paused outside of her brother's door to hear the voices within. It had been a hectic day, her brother had, had another attack, and the others were worried.
She heard Jems voice inside.
"What is it Will? Tell me the truth, no more lies,"
"I'm in love with Tessa." He whispered, as he sat on the bed "I am sorry James, I tried to hide it and fight it but I could not, I am sorry."
There was a silence, as James considered his reply "I'll call off the engagement."
"No! No Jem, I couldn't be happy feeling your pain, don't leave her."
"And what about my sister? I asked you not to hurt her"
"She's a good person, a wonderful heart…but no…no I am not in love with her and I do not believe I ever will be."
Another silence.
"I asked you not to hurt her-"Both of them were cut off when they heard the sound of smashing plates.
Will opened the door to see a tray had been dropped. But no one around.

Rosalie slid to the floor of her bedroom, and sobbed and sobbed and sobbed. It took a few hours before there was a knock on the door.
"Rosie? I can hear you crying...what's wrong?"
Will.
She didn't reply, and so he knocked again, before easing open the door slowly. Rose didn't look up as she felt someone sit beside her and pull her into their arms. "You love her" She whispered numbly "You lied to me" She felt the person, Will, tense
"You heard that…"
"My brothers dying, I am dying, and yet you break me. Get out. Get out before I pick up my knife and gut you – you Hùn zhàng!" (Bastard)
"No – you are Jems sister, a friend; I promised not to hurt you-"
"Yet you fall in love with her!" She stood up, "You can tell my brother that he loses the sister he just got back because of his parabatai." She had already packed her bags…

So I'm just testing the water as I wasn't sure, maybe if you guys like it I'll continue/start from where she first arrives Thanks.