My roommate is making me hate all smokers by association....even though I know that's wrong

Backstory:
She's technically an illegal roommate, meaning she is living with one of my other roommates in violation of the rent agreement. She got reported and they covered it up so she's still here. That's a whole other bag of worms.
Well, one of the tell-tale signs of her living here was that the grounds crew kept finding a large pile of cigarette butts underneath our balcony, and the grounds have designated smoking areas. Our balcony is not one of them.

So....

The last week our kitchen has been rancid with the smell of cigarette smoke.
Granted, I'm super sensitive to it, being allergic to it and all.
I traced it to the garbage can but didn't want to paw through the nasty mess in search of evidence so I merely doused the thing with bleach and moved it out of the kitchen, hoping someone would get the message.

Today:
I'm cooking, trying to hold my breath and trying not to think about my family history of lung cancer, my lack of health insurance, my expired inhaler, or my tickly burning airways...when I find a butt sitting there on top of the garbage.
I wanted to storm into the room and shake her like a rag doll.
We'd already had one discussion about how I was allergic and preferred her not to smoke right outside our door, which never quite sunk in.
Also, I'm flipping paying for her rent and utilities, while she slowly kills me with second and third hand smoke.

AAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHHHHH!!!

So I finally knock on their door and here's the actual conversation:

Me: Uh, hey, are you throwing cigarette butts into the kitchen garbage can?
Culpit: *sits up and stares at me*
Me: *waits*
Sister of culprit: Yeah, why? *without looking up from video game*
Culprit: *still staring like a deer in the headlights*
Me: Well, because the whole kitchen smells and *I look right at the culprit* I'm allergic to cigarette smoke...
Sister of culprit: Ok.
Me: ...and it's making me sick so I was just hoping you could not do that anymore.
Sister of culprit: We can do that. *still not looking up*
Culprit: *Still staring silently*
Me: Ok, well, uh, thanks.

????????????

"Why?" !??!?!?!?!
Why do you think? This is a non-smoking apartment, I've discussed my health issues before, I should not be subjected to your self-destructive habits!!!!!!!!!!!! If you want to poison yourself that's your business, but you damn well better make sure I don't suffer from it!

I really wish I could, like, have an asthma attack in the kitchen, die, get her charged with manslaughter....and then come back to life.
Or at least give her a really vivid dream of such a scenario.

I am so angry right now.