My daughter doesn't turn in her homework either. I get the progress report and ask about it and she pulls it out of her notebook and shows it to me. WTH? I asked how hard it was to turn it in...I just don't understand it.
I have to admit my sister and I fought all the time. We are 16 months apart and she hated me growing up. I used to sleep with a tennis raquet because she once told me that she would beat me up while I was sleeping. She was bigger and meaner than me. I would run screaming and hide behind my mom. One day when she was 18 and I was 17 (yes, we were old enough to know better) she hit me and I got mad. I finally hit back. After 15 minutes of my mom screaming, us breaking her marbletop table and me punching my sister in the stomach and ripping her earring out of her ear she has never hit me again. We actually got along after that.
My girls are almost 3 years apart and for the most part get along great. About 5 years ago when they were 11 and 14 they kept arguing and hitting each other so I went out and bought boxing gloves, moved the furniture and told them to go at it. They looked at me like I had lost my mind. Since then I haven't had any major problems with them getting along. Now they are almost 16 and 19 and are best friends.