Flirt with her.
One of two things will happen:
1. She'll be into it and you can collect evidence of such and show it to your dad, or
2. She'll find it awkward and leave you alone.
There is no possible bad outcome to this approach. This is what you should do.
C'mon, guys, there are those naive enough to think you're serious! :o
All I can suggest to to suck it up and be polite. Go to school, or get a job, and get out of the house; you are on the cusp of the next great phase of your life.
I do have a question though, do you do your chores properly? If you are slacking on your end of things, and not pulling your weight in the household, than you are only giving her nagging legitimacy.
Get a job, this way you will have some time to stay out of the house and safe your paycheck so when you are 18 and out of high school you will have some options.
If you still have some free time, do your homework in the library before heading home. Does your high school have a weight room available after school? Take that negative energy and turn it into something positive like being in better shape, exorcise can also be a major stress reliever.
Time your arrival home with enough time to do your share of the housework and then get to bed.
Stay focused on something else and keep yourself out of the house. Eight months will go by in now time.
When you are home try to stay out of her way and try and be the bigger person. It sounds like she will be this way for the rest of your life. You only have eight months until you can move on to something better,
This is the number one reason I didn't remarry until my kids were grown up. I've seen and heard of too many blended family nightmares and I didn't want to become one of them. From my experience, teens whose brains are still developing in the area of emotion and impulse control, can be irrational. It's part of growing up and learning to manage your emotions and handle conflicting situations.
Stay busy, focus on education, continuing education, working and saving money. Use your home to eat, shower, sleep and be politely neutral and do your chores.
Use these last 8 months to plan for your future. Get help if you need it. Enroll in college, perhaps dorms. Enlist in the military, the peace corps...you have lots of options. Refocus your negative energy into self positive energy to excel and succeed in life. My son Jacob had his room packed weeks before graduation and went to India for 6 months to work with children. Then he went to Chicago to a Bible college for a year. He's now married with a baby and finishing up his last few semesters of a Civil Engineer degree.
Take control of your life and take the leap of teenager to man.