I don't own Harry Potter, I wish I did but I don't. Especially George. The things I would do to that boy...

This is just the outline of how Cassidy becomes part of the Weaslys, though I hope she'll turn out different than you expect but this is just an intro chapter.

This is the first time I've let anyone read my work, so r&r.

2001

"Boys, for goodness sake will you pack it in? Bill it's not like your brothers need any more encouragement. Fred, George if I have to tell you one more time -" Mollie scolded, but was cut short by a wail which cut through the air like a knife, making everyone fall silent in a matter of mere second.
"Arthur what should we-" began Mollie in a hushed whisper before Arthur managed to catch her terrified eyes and with a single look, she nodded and watched him silently as he snatched his wand up from the cluttered table and ran out of the house, his heart sinking with every step he took, petrified on what he would find on the other side of the wall, the ice crunched beneath his feet as he perfectly still stood behind the wall. His breathing became shallow as he began to get worried about not being able to protect his children, his wife – all of his reasons for living.
With a deep breath he leaped over the crumbling wall with his wand outstretched, staggering backwards at what sat before him. It took him a moment but once he overcame his initial surprise he knelt down putting his wand in his pocket as he held his hand out to her.
"Hey there, can you tell me your name little girl?" he asked kindly. His eyes glancing at her up and down, his breathing slowing down once he realised that this couldn't be a trap. She had tears falling silently down her face as she was scrunching into a tiny ball, whipping her head up when he spoke to her.
"Cassidy, urm... I don't remember," She whispered, her crystal clear blue eyes wide with fear.
"That's okay Cassidy, my names Arthur Weasly; do you know where your mummy and daddy are?" He asked as calmly as he could, it must have been her, he thought, but why did she scream like that?
She shook her head, making a few more loose strands of her inky black curls fell out of the loose pony tail, falling into her eyes, making her look more disturbed than before.
"Well do you know how you got here?" he asked, frowning. The Burrow was miles away from the tiny local village which was miles away from anywhere else. How on earth could such a tiny girl have travelled here all by herself in the middle of winter? He looked at what she was wearing and a wave of pity hit him – she had on a tatty green velvet dress which looked like she had grown out of months ago, and cut off at the knee, which was making her shiver and pull her legs closer to her chest.
Instead of answering his question, she frowned herself, her eyes dropping to the ground as she asked in a small voice, "Are you a good person?"
Arthur tried to not let the surprise of the question show on his face, or in his voice when he replied, "well I like to think I am, yes."
Without saying anything else her clenched fist opened up and she handed him a letter which looked as if it had been written in great haste with ink splotches all over the page, Arthur looked at the small girl before him before opening the letter;

Take the girl; blood traitors have more use of a dirty
squib than we ever will.

"Who gave this to you?" he asked, trying to keep the anger out of his voice as he re-read the two lines in front of him over and over again, glancing up at Cassidy, only now just noticing the green bruised tint to her jaw line.
"I don't remember," She whispered, "it was a bad man though."
Arthur sighed, and stood up, glanced down at the tiny girls huddled figure, shivering ever so slightly and held his hand out to her. She flinched ever so slightly which made Arthur have to concentrate even more on his voice, he didn't want to scare her away, not now. "It's okay," he said softly, "you won't get hurt here."
She looked up at him, her piercing blue eyes looking as if she was reading his mind, before she dropped her head down, and without a word stood up, more gracefully than Arthur had ever expected and slipped her ice cold hand into his.
He lead her back into the house and opened the door, everyone was still, in the same position as he'd left them in, their eyes widening when they saw Cassidy hiding behind Arthur.
"Bill, Charlie can you take Ron and Ginny upstairs please and keep an eye on them," Arthur said, clearing his voice, breaking the tension in the room in seconds, "Fred and George can you take his little girl here," he said pushing her forward softly towards the twins, "and get her some warm clothes to put on okay? Make sure you're nice," he smiled as he let go of Cassidy's hand as she walked forward towards the boys hesitantly. They both took a hand each and whisked her upstairs and before she could even think about it, she was sitting on their bed.

"I'm Fred." One said.
"And I'm George." Said the other.
"And who are you?" they said together, sitting down either side of her.
"Cassidy," she whispered, her head bowed down.
"Huh," they jinxed again, "and how old are you?"
"I'm six years old," she said with a bit more confidence, daring to lift her head up and to meet their eyes for a second, feeling warmed at how happily and innocently they looked back.
"We're eight, we'll be nine soon." They jinxed again.
And Cassidy giggled, she didn't know why but it was something about the pair of them which she smiled at, made her feel safe even though she'd only known them for a matter of mere minutes she felt home.
"What are you giggling at?" Fred poked her smiling, cocking his head to the side, his orange hair falling in front of his face, framing his warm brown eyes, making them glitter in the candle light.
"I don't know," she said, barely above a whisper but still, when she realised there was no retaliation for her speaking she lifted her head up with a bit more confidence and let out an involuntary shiver.
"Oh yeah, clothes!" George remembered clicking his fingers, diving into the wardrobe almost head first, and the clothes around it breaking his fall as he began chucking clothes backwards. He picked up his favourite top, the only top he could be certain was clean and handed it to her. She smiled at his meekly and stood up and walked towards the door and paused just before she reached it with her hand on the door handle. "Where's the bathroom?" she muttered.
"Last door on the left," Fred said off-handily already distracted by one of the colour change marbles which had rolled onto the floor in front of him.
Cassidy pushed the door open hesitantly and looked back, hesitancy etched in her movements, and George understood.
"Want me to show you?" he asked, flinging the clothes which he was half way through piling back into the wardrobe onto the floor, as he leapt forwards.
She nodded slightly and pushed the door open, taking a small step out from the bedroom and waiting in the hallway for George, she only came up to his shoulders and he couldn't help but to feel a weird jolt of happiness when they brushed skin walking down the tiny hallway. George indicated to the bathroom door, and held it open for her, "want me to wait outside," he asked, before he closed the door.
She tilted her head to the side and smiled, "yes please." Before shutting the door.
George waited outside patiently, he could hear his mum and dad downstairs, and even though he couldn't make out what they were saying he knew what it was and he knew what was going to happen. Something had happened to lead Cassidy here, she was going to stay here as long as she wanted, and that one day he was going to marry her. And with that safe in his thoughts, the door opened to reveal a much cleaner Cassidy.
She'd tried to pull her curls up into a pony tail of which a few loose curls escaped framing her shocking blue eyes, her skin looked a lot paler than George would have thought it with all the mud and dirt washed off it, the ruby red top he'd given her falling to her knees, as she carried a type of unaware innocence that only a six year old could do.
But it was the bruises was what made his heart beat quicken, the blue and green blotches covering her body that he could see, making his blood boil. She noticed him staring at them and tried her hardest to avoid his eyes, which were trying to meet hers. He held out his pinkie and she looked at him confused, he coughed to clear his throat and said, "You'll live here now, and I won't let anyone hurt you ever again. Pinkie promise," he waggled his eyebrows comically at the end, but even Cassidy understood from the sincerity of what he said that he meant it, and she nervously stuck her finger out as well, and they linked fingers and smiled at each other.

"Well that's lame," Fred laughed, poking his head between the pair of them, poking George, "are you turning into my sister Forge?"
"No," he poked back, "though if you carry on, I'll make mum turn you into a girl."