Hi C.,
When my daughter was 13 she started to exhibit laziness. When "asked to help around the house, she tells us "no, I don't want to" in baby talk. Only when we tell her that she can't watch t.v. or eat a snack, does she comply. As for sibling rivalry, she is constantly calling her 16 year old brother names, and vice versa.
I don't know if this will pass soon, but most of the time, I just am in resentment mood, and retreat into my room to get away from it. The one time she said "I hate you", I replied "I know, it shows by your disobedience and dis-respect!"
I have declined from doing anything around the house as far as extra cleaning, by doing just the laundry, running the swiffer to pick up the weekly tumbleweed of hair left behing from the dogs, and cleaning the bathroom once every two weeks. For the most part no one cares if the house is a mess. Currently there is a banana peel on the back of the new leather sofa...it has been there 2 days! My daughters room has gatorade and plastic bottles strewn all over, last count was 15.
My husband is retired and has become a pack rat, with almost every room in our house that should be sorted into three piles.
I do know that it will be a glorious day when I can visit their home for a week, with a bunch of banana's, and gatorade!
So for now, all I can say is perhaps if you get your 13 year old into a church outh group, she will develope some better appreciation for you and her siblings. May I recommend Southeast Christian Church in Parker?
My kids won't participate in their youth group at church, but rather want to sit with us. Go figure.