Sharing a bathroom with a 13-year-old

The thing about the rant you are about to read is, it is purely my personal experience with my 13-year-old little sister. I'm sure not all 13-year-olds act this way, and I'm sure gender plays a huge roll. Guys don't use the bathroom the same way pre-teen girls do.... With that said.... Here is my unfortunate experience of sharing a bathroom with a 13-year-old.

On any given day I will walk into the bathroom with hesitation, a sort-of gingerly step as I walk in, and I hold my breath as I turn on the light. When I walk into the bathroom it is a guarantee I will find one of these scenarios. The first is usually a layer of skin colored powder lightly dusted across the counter, left behind from her morning make-up routine. But not from just that morning, she has accumulated a little each morning, so now, it is a tiny layer as thick as maybe baby powder. The second thing I turn my attention to is the floor. Understandably there are clothes on the floor after she gets out of the shower! She is a human being after all, but the clothes on the floor are from the shower she took three days ago, underneath the clothes from the shower she took two days ago, which are hidden under the clothes from yesterdays shower. As if this mountain of clothes isn't enough, the third place I look is the toilet. Where more often than not, she will leave little-to-no toilet paper on the roll. I know walking one and a half steps (past the clothes pile) to the closet to get a fresh roll would be doing something useful... but this is usually my last straw! Sadly, its not the last thing I see! When getting in the shower it's not uncommon to see a bandaid that she took off and has just carelessly set to the side. If I don't say anything, she will let it sit... and rot! That goes for all the things on this list. If I don't say anything, nothing will get done. In the shower, I often find those clear plastic caps that go over the blade of razors. But I don't find them on her razor, I find them on the floor of the shower where I step on them, or they are falling down the drain! And when I pick up the stupid clear cap and go to throw it away, I find the trash can full to the brim, even spilling over! Full of used make-up containers and endless tissues she used in the make-up process, bandaid wrappers, toothpaste tubes, and much more. Don't even get me started on the toothpaste clumps left in the sink.
I've asked her to keep her things on one side of the counter so I can keep some sanity on the other half. She followed the plea for a while, but then realized the outlet is on my side. I understand that she needs to use it, and kindly let her, cause we are rarely getting ready at the same time. But she leaves her hair straightener on my side when she is done! She lets the plug dangle down to the floor so when I am not paying attention, I step on the plug part, and shout in pain! I would say her straightener is the MOST consistent annoying thing. I have not walked into the bathroom since the summer when it was not on my side of the counter just taking up my precious space.

As you can imagine all this builds up inside me, and I get on her about it. She is old enough to clean up after herself. But it gets tiring to do it everyday! I don't have the time. On the occasions I do, she rolls her eyes, says she either "forgot to clean it up" or "it's not that big of a deal." She does, though, get off her butt and hastily does what it is I ask her to do, whether its pick up her clothes, put away her straightener, or take out the trash. She does it poorly though.... When I ask her to wipe the counter she misses big spots, and when I call her on her crummy job, she claims she "can't see what I'm talking about." Getting my parents on her case is like putting duck tape over a hole on a floaty, it's a temporary fix. Gets the job done that one time, but won't fix tomorrow's problems.
I've tried the anger approach, I've tried the passive approach, I've tried the "meeting her on her level" approach, and I've tried putting little rules posted throughout the bathroom. Nothing seems to phase this kid! I dread the day I leave for college and she goes unmonitored on a regular basis! That bathroom would be condemned by now if left under her control! I do all the major washing and scrubbing anyway!

I've gone to the end of the world and back to get her to keep this bathroom at a functioning level. I feel like I'm constantly treading water, like its an endless battle I'm never going to win. But I can't give up and give in, or I won't be able to use my own bathroom! Pretty sure whatever dorm bathroom I'm in next year will be better than mine now. So yah, thats my terrible bathroom experience. Wish me luck in my continued efforts to make my sister an acceptable functioning human being!