What a good and sensible friend your daughter has. My / my daughter's situation is so different from what you have experienced, I can't address any of your other questions. I'm sorry about your friend's tragic history. You may be nipping in the bud an even more tragic life, by making it possible for her son to get any help that may prevent further abuse on his part. You will have to keep your daughter in sharp focus as you proceed so you don't let the feelings of others interfere with your being the best mom you can be.

We reported ours to DCS - who then did a forensic interview with your daughter (where someone trained to ask the right questions gets what happened out of the victim in a gentle way). Him living out of state my limit what your state can do, but I would start with DCS. After the forensic interview, they then work with law enforcement to work on things. Here is a link to several different options that you could start with before going to law enforcement. Your daughter should be protected and should not have to talk to multiple people, and starting with DCS may be better than starting directly with Law Enforcement.
http://www.d2l.org/site/c.4dICIJOkGcISE/b.6069291/k.502C/National_Child_Sexual_Abuse_Helpline.htm

We went to the ER and reported it to the police there and they sent us to a child advocacy center where my daughter was forensically interviewed and examined... Good for your daughters friend for convincing her to tell...!!! i think that going to the police station would be best and maybe requesting to speak with a female police officer so your daughter is more comfortable... Prepare her for this by telling her she is a hero for speaking up and that she would be protecting other girls from
Having to be assaulted in this way by this person... That it is the best way to make sure no one else gets hurt the way she has been hurt. It's sometimes hard for victims to think about protecting themselves but if they begin to think of other girls having to go through the same thing there is more courage to stand up and say enough is enough...!!! Best of luck to you and your little one... I'm truly sorry your going through this

My experience is different than yours. So this response may be more for others.
Sometimes abusers threaten kids not to tell
And abusers will instill an intense fear of the police
Often kids will be too scared to tell anyone other than their protective parent - which places the entire family in danger when kids only tell a parent and refuse to tell anyone else (which gives inept counselors etc the impression that the protective parent is coaching)

So my point is - when deciding to report you need to always consider two things
1. Was your child instilled with fear about disclosing to any particular person that by placing your child with that very person for disclosure will be traumatic? It's also very difficult for children to disclose to a stranger about this embarrassing situation. Sometimes kids will prefer a male / female again because of the sensitive personal nature of this and considering that the abuser too most likely is a male.
2. Is your child likely to disclose because you want to avoid the trap of the appearance of a coacher (which by the way means not being in the room at the time of disclosure)

We went to the doctor so a professional medical person was involved. They are required to report it. We were referred to an abuse group who told us to call the police and report it as well.

Please pull as much strength from our group of supporters as you can. There are days when this is all I have and I am so grateful.

I should have probanly reported it by now, my daughter wasn't ready and I felt like she needed some time, I was numb for a few days and have researched day and night.I have not even called her therapist and told her yet.I feel sorry for my inlaws. This is their dead son's son and it is going to kill them. My mother in law knows but she does not know everything as I have found out more yesterday,luckily not too much more happened.I am not sure that anything will happen to him as he was only 13 but now my inlaws will have to choose at holidays and family events because my daughter never wants to see/talk to him again. I am not even sure she will be able to go to my in laws house since it happened there.How does a family get through this? my sister in law and the boy are coming here for a weeks visit, will be here Saturday and unfortunately I am going to have to report this very soon, probably tomorrow.I am not trying to ruin their visit because my inlaws have not seen them since December.Did I mention he(the perp) has a brother my daughters age?My mother in law is VERY close to those boys and especially since their dad died. They use to live close but my sister in law moved out of state to afford to live,I know my first priority is to my daughter, I just feel bad is all.If they turn their backs on us I am not sure my daughter will be able to handle it. I guess I am just afraid to start a big thing for my daughters sake, I know it must be done. BTW a question, is it weird that my daughter would rather go to the station to do this? I am thinking she does not want to do it here at home because this is her home,Is that weird? Normal? I don't want the authorities to think I am trying to hide something.

No it isn't weird, and honestly I think if you call a hotline they will direct you to DCS rather than law enforcement (we never had to have any contact with an investigator, only a forensic interviewer). I am not sure what will be done as he lives in another state which will complicate matters - but just because he is was only 13 doesn't mean nothing will be done, our offender was 13 when this started and is now 14 and has been charged in Juvenile court and will likely be on a sex offender list when he turns 18 until he is 25. You will get through this, and the family may be torn apart, but you have to do what is best to protect your daughter. It is the hardest thing you will ever go through - as my son said, it is worse than death,because most of the time with death you are dealing with one person, we have lost an entire family. Hang in there, no one is going to think you are trying to hide anything as long as you take the proper steps.

Even if you don't lose any family members, it's worse than death, because your child continues to suffer, and because the child you knew was stolen from you, and the truth of this is eternal. Death is easy. The bigger challenge is how to keep going so that you can live fully again. Keep your mind on what's best for your daughter, and on how you can take care of yourself, and leave the rest to your spiritual higher power -- you can't control these other people, no matter how much you love/loved them. You can only take care of yourself and your daughter, and the days will move forward.