The lost Weasley

Prologue

Five year old, Katherine was sitting in a swing set just minding her own business until a mean bully who was also an orphan pushed her rounghly.
Katherine was already used to the harsh treatment of both the other children and the grown ups at the orphanage. It was a magical orphanage so Katherine knew she was magical.
The other children surrounded her and continued to punch and kick poor Katherine.
The last thing Katherine saw before fainting was a boy not much older than she use underaged magic to pull the bullies off her.

Two weeks later, Katherine woke up having trouble breathing but the boy who helped her started to help calm her.
A woman no older than 22 walks in and starts to bandage Katherine up using her wand.
"Thank you both of you." Katherine mumbles under her breath.
"It is not a problem deat, Jacob found you and he brought you straight here which was a good thing too cause if he hadn't another hit to the head and you would have died." The woman said in a sweet voice.
"Mum!" The boy complained even if the woman wasn't his actual mum.
Katherine whinced as the woman tightened the last bandage wrap.
Katherine looked at the boy and asked in a weak voice, "She is your Mum?"
"No not really but she has became like one to me since two years ago when my parents were killed by Death Eaters." The boy explained with teary eyes.
"Ah," Katherine said wheezing from her broken ribs.
Katherine had a fractured scull, broken right femur, and three broken ribs.
Katherine looked at herself and saw a big fat white cast running down her entire right leg she frowns.
The boy places a hand on Katherine's good knee and smiles softly.
"I'm Jacob by the way." The boy introduced himself.
Katnerine nods and says her name.
And from that day forward Jacob and Katherine became best friends ...