SOLVED. Fantasy YA book from early 2010s: a half shadow/human girl thinks shes human & jumped around foster homes her whole life. a shadow detective shows up and tries to stab her bc hes been looking for her and im running out of characters. [s]

[el]

this book is a fantasy/sci-fi ya novel published between 2011 and 2014 (rough estimate) and it may be the first in a series but i'm not sure. it has a pale blue ( i want to say baby blue to light turquoise?) cover with translucent human outlines on it. i read this book somewhere between 2015 (maybe 2016?) and 2012? its a wide range but i don't remember a lot about the years, but i know the plot. it starts with a high school girl (i want to say shes 17) who's been bumped around foster homes her whole life and all of the other foster families have tried to kill her because they think she's possessed. the last foster mom threw knives at her they ended up shattering the fish tank in the living room? she's been with this foster mom for a decent amount of time but she knows everything will come crashing down soon (it doesnt, even after she disappears and the house is trashed-- im pretty sure she actually wants to adopt her & still does at the end of the book?) a new guy transfers to her school and she's really interested in him. (i think they have english together?) and he comes over to study but then i think he attacks her? there's something about him trying to stab her but instead i think his pen stabs her water bed. he ends up putting her in cuffs and it turns out hes a detective who was undercover but he isn't human and turns out she isn't either and he brings her to his world. because she belongs there apparently? but not really because shes half human and everyone hates her?it's in chicago, but another version of chicago (the great fire split it or something?) but everyone there is a shadow/ghost thing? except for the protagonist shes half human and then theres one girl that REALLY hates her and i think its bc she's in love with detective dude? when detective dude is in love with the protagonist and shes in love with him too but hes all "no, im supposed to protect you, it isnt right" and he used to do art or paint a lot but he's stopped and she gets him to paint again (i remember them talking about how long oil paint takes to dry?) also i think there might have been a weird age gap i remember those vibes. but then something happens and a fire starts, but i think she stops it and now no one hates her anymore? also i think she can shoot fire out of her hands but i'm not sure. all i really know is that i dont remember what book it is and i'm literally losing sleep over it. someone help me please im begging.

[Rose]

Shadow Girl by Sally Nicholls?

[Rose]

Or the The Shadow Society by Marie Rutkosi?

[el]

the shadow society!!! thank you so much! :))