What causes conflict in your household?

i am a very concern parent, i dont spare the rod for my children, i love them and show lots of it. i attend school pta, take them to church, i often pray for them and over them, i make sure they have clean clothing and food to eat, my oldest daughter is the only one i dont understand and why she act the way she do. she loves attention and to talk back, its a none toleratings in my house. she is very,very smart and creative, loves to sing, write poems, and draw and can be very helpful. after her dad i seperated at one point it became worst, i love my child and just want whats best for her.