Sounds like ADHD or a related neurological condition. You should have her evaluated by a pediatric psychiatrist or neurodevelopmental specialist. Parenting her like your other children is only going to further stress your relationship and her mental health and psychological development. As a parent with a child with ADHD (and a husband and brother), if this is the diagnosis or not, I recommend the book The Explosive Child and From Chaos to Calm, both of which talk about the sorts of problem you mention here. If she does have ADHD, the book The Energetic Brain does a good job of explaining the neurobiology, treatments, and practical info for ADHD, though the school info regarding legal rights, etc is US specific, which isn't helpful to anyone outside the US.
I completely agree with Sandman. I'm sorry she is struggling (which is what this is) and I'm sorry as I know it is really hard on a mom. Sandman has given you excellent advice to look into as this sounds neurological in nature. Please don't be afraid to go down that road as we need to help our kids be the best they can be. It can take intervention of the medical kind when it is a neurological issue at the heart of things. Let us know what you think and how it goes, okay?! good luck
Problem children do not need punishment. It only makes the scenario worse.They are problem children because they want attention. Perhaps, your child feels like you are not giving her enough attention, and perhaps she feels rejected. It is a sign that she wants you to spend time with her.
Taking your child's phone, computer, or tablet is not going to do anything but make her resent you. Definitely do NOT send her to boot camp. Children get raped, molested, abused, and beaten at boot camps. It may change their behavior, but they go into the world seriously messed up mentally and emotionally.
But,you would receive the same effect talking to her for a few hours and spending time with her rather than sending her off to a boot camp where she will receive verbal degradation and much more or a boarding school
Try talking to her. Make her tell you what is wrong. And I am not saying with physical interaction, just keep pressing and asking her what is wrong until she finally decides to tell you. Then you can solve this issue.
And maybe it is not the fact that she wants attention. It could be the fact that she is trying to act like other children. There are certain children that will basically train other children to do what they want. This child that told your child to google porn, may have an influence on her behavior.
And sometimes, you will be surprised to know how many children have been touched inappropriately and how this has a negative effect on their behavior. It change their life permanently. If she is being bullied by other children at school, she may not tell you.
Her abusing other children may be a coping strategy in her mind. It could also be peer pressure. She may want to seem cool to other children, so she acts poorly for the entertainment of other children to be accepted. Some children just do not have a sense of self-identity. Some are obsessive and clingy.
Some children thrive on attention. As a child I had a friend that throve on attention, because she did not get any attention from her parents. She always wanted attention. As she matured, she quickly realized that she did not need to have attention from everyone. She had her own personality. She also resented her parents.
That dread of every parent. Resentment. I do not think that it is Attention Deficit Disorder, or Attention Deficit Hyperactivity Disorder or a psychological disorder. I think that is simply either A.) a need for attention, or B.) peer pressure. Many parents I meet do not pay much attention to their children or, they feel like they do not need to be friends with their children, but they are wrong.
Children who grow up without friendships and strong relationships between their parents and some sort of self-worth/being have a very demented and destroyed perception of the world. They will have either have children and take the problems out from their past on their children and use it as a barrier to cope with the pain and betrayal they feel, using either physical abuse or verbal abuse, or they will avoid having children because they do not want their children to have the same perceptions of the world.
They also have many commitment issues. But talk to your daughter, spend time with her, let her know that she is a diamond to you and that she is special in your eyes-- tell her that you love her and hug her, and you should see improvement and a complete change in her behavior.
Send he to boot camp. Seriously I was a terrible child and this helped me tremendously
CamHS, oh golly, I have heard this complaint more then a few times. This link might help you get faster services.
http://www.youngminds.org.uk/for_parents/parent_helpline
Next your daughter is showing many, many traits of ADHD. Which would also explain why none of your things have worked to change her. This link gives more info on ADHD (and I have plenty more if needed).
http://www.additudemag.com/adhd/article/784.html
And perhaps your school can intervene and help with Cam. Tell them you think she has ADDH (if the link above makes sense) and needs help.
The lack of sleep at night is also a very strong symptom of ADHD. It is also a reason why she has some of her problems during the day. If she can start getting more sleep - you will see a difference.
Here are link of two on ways to help her sleep and what it can do to help her.
http://www.additudemag.com/slideshow/22/slide-1.html?utm_source=eletter&utm_medium=email&utm_campaign=december&mc_cid=de2b5eef61&mc_eid=34d357d554
http://www.medscape.com/viewarticle/838428_1
Finally, as you have noticed the traditional discipline methods just don't work that well. However, there are some very good methods for working with ADHD kids. Oh, as you have also noticed, what you are doing at home in terms of discipline will not really carry over to school. It is a waste of your time to punish her for what happens at school. What you can do is to slowly try and change certain behaviors at home that will carry over to school. These links will help.
http://www.additudemag.com/slideshow/100/slide-1.html?utm_source=eletter&utm_medium=email&utm_campaign=July
http://www.additudemag.com/adhd/article/860.html
I hope this helps a bit. I have a lot more info if you need it. Best wishes!
Perhaps instead of punishing her, you should talk to her, because it seems that there is a larger problem here. Punishing her will only make her seem more rejected and like a "bad kid." But if you take a step back and realize there may be more in play here, having a meaningful discussion with your child about what is going on in her life could be the help you really need. Be warm, forgiving, and kind, and make sure she can open up to you, and most of all DON'T JUDGE. Good luck!