Hey there TrzVpr. Aside from being a legal advice forum, it is populated with human beings who all have personal experiences and opinions. This forum has no rules about sugarcoating or "playing nice" so you're going to get "bashed" a lot when you post here. You can either go on the defensive (which most people do) or glean the meaning behind the mean, curt, incomplete or downright nasty posts.
You DID get a legal answer; in addition, you also got a moral answer. The unanimous moral answer was to get away from her, to preserve her development and your career/future.
Legally, you could be in a sh!t-load of trouble too. CdwJava was good enough to post the codes that apply.
What the people here are "bashing" you about, is you apparent unwillingness to make a decision, to make it yourself, and make the correct one for all the parties involved.
Sure it's ok in other countries (even other states) to be in a relationship that young, but here, where I live and where you live, the majority of people believe that at 15-16 years, you are not capable of deciding with any objectivity, your current mental/emotional state, future ramifications, etc. etc.
So please take the comments here two ways: with a grain of salt (because there's usually useful info in offensive posts) and with the understanding that we are speaking from our own perspective.
This may be a waste of time to type out (for many reasons, including the possibility that you're already fed up with us), but I felt something needed to be said.
Please don't continue with this relationship. Tell her the truth in a letter or over the phone. She will cry and say that you guys can work things out, or that no one has to know... but once you pull yourself away she will be able to grow up the rest of the way, have the life a young teen deserves, and she won't ever regret becoming involved in something before she was ready.
BTW, the last half of that sentence was from personal experience, so I'm not talking out my a$$.
I hope you understand where we are all coming from.
Gryn