Legal info about child porn?

I am lost. So my friend is seventeen and her boyfriend is older and the took some naughty pictures together and my seventeen year old friend took the pictures and put them on her boyfriends computer..and her boyfriend posted one picture of them on the net...why is she in trouble? I understand why he is, but why is she in trouble.

I don't know. For starters, it depends on what you mean by "in trouble".

For criminal prosecution:
In most states, the person who the statute is designed to protect (the underage person in this case) cannot be prosecuted under the statute. Perhaps in your state she is considered of age for the purpose of the statute and is being prosecuted for being an accomplice to some crime, which she may or may not be guilty of. I don't know what crime that would be or why anyone would prosecute and the facts you stated don't indicate this as a likely possibility.

Other than criminal:
A school or parent or some other entity that may get your friend "in trouble" doesn't have such restrictions. They can punish her for poor judgment in allowing the pictures to be taken if they see fit. A public school generally only has to afford you the opportunity to explain. That's not to say a public school can do whatever they want provided they meet that minimum due process requirement though.

This is not legal advice. I am not a lawyer yet. If there is a criminal prosecution, your friend should have hired a lawyer or if she can't afford one, one should have been appointed for her. She should ask that lawyer. If she wants to challenge some other disciplinary action, like a suspension or expulsion, she should contact your state's bar association or civil liberties union to see if there's anything she can or should do about it.

"...my seventeen year old friend took the pictures and put them on her boyfriends computer." She is an accomplice.