Need some help NOW!

My brothers ex girlfriend was 7 months a long and mysteriously she I at pregnant anymore u til today when she picked up her son from my brother. This new baby she was about to have wasn't his. And she talked about giving it up for adoption, and she also has been using drugs/alcohol her whole pregnacy so I. Sure the child would have issues. From yesterday to today is when she should of had the baby.... We think she had an "at home abortion" and got rid of the baby herself. Is there anything we can do about this if this did happen? It is pretty much murder!!! We ask and she says it's none of our business. Can we talk to humane services and then can they get info about if she did have the baby at a hospital? And if it was stillborn, did she need to see a doctor legally? This is totally WRONG, and I will be calling someone tomorrow, just need some advice on who to talk to and IF anyone can do anything. Please please please!