Should this really be a law?

A lot of people are blogging about sexting and how they feel about it. It is quite obvious that possessing child pornography is wrong and should be illegal. However, we need to take a non-positivist approach to this. We have to look at the facts of the case and not just prosecute because the law says to. A realist would look at a case involving a 15 year old girl who has naked pictures of herself on her phone and ask themselves, does she deserve the same punishment that a middle aged man with naked pictures of a child should receive? A positivist would say yes. This just doesn't seem right to me. However, i see the predicament that lawmakers are in. They have to make laws that apply to everyone. No one should receive special treatment in the eyes of the law. Getting convicted of possessing child porn can have the consequence of labeling you a sex offender. So let's say that the 15 year old is convicted of having naked pictures of herself on her phone and has to register as a sex offender. That means that pretty much any career she wanted to get into that involved children is no longer available, all because she has naked pictures of HERSELF on her phone. This does not seem fair to me. Now in the eyes of a traditional natural law theorist, she is morally wrong to some people because porn is morally wrong but she is doing what makes her happy and that is what natural law is all about.