Part of your Memory (hpff- Sirius Black)

It's not bad being different or is it?
When Cosette finally leaves her abusive foster parents it seems like she is alone in the world, even her old best friend, harry potter, has fogotten about her and found new friends at the new school he has gone to. But after following him when he leaves his aunt and uncles, she relises that there is more to life than her world but there is one filled with magic.
Soon being different is the best thing that has happen to her but when she tries to uncover who her father is, the more she wishs that he never existed.
And what happens if she meets a stranger in the woods who so happens to be a killer on the lose. Will she believe he's innocent or will she turn him in? what happens if she falls in love with someone who may not like her back?? ANd will harry remember who she is or will she just be part of his memory????????
READ TO FIND OUT

Sorry if the description sucks but please do read my story cause hopefully its a bit better 0_o