My contribution to this collection of short stories edited by Michael Cart is called Dr. Jekyll and Sister Hyde. It's a story about a fourteen year old girl named Sasha, who has an "evil sister" who makes her life miserable. 

Here is a poem from Dr. Jekyll and Sister Hyde:

Lucy's chasing me down the hall again,
like a fire-breathing dragon,
hands clawing the air at my back,
calling me words
I've never even heard before. 

I'm swallowing a scream,
racing through my bedroom
towards my bathroom door,
shoving it open,
ducking inside, 

slamming it hard behind me,
and fumbling at the lock
with stuttering fingers,
till I somehow manage
to snap it into place. 

Now I'm leaning against the door,
while Lucy slams her fists
into the other side,
my heart fluttering in my throat
like a trapped bird. 

I'm sliding down onto the cold tiles
and reaching behind the hamper
to find the book that I keep hidden there
for whenever she has me cornered like this,
wondering how soon our parents will get home. 

She never hits me in front of them.