I wish I has seen this thread when you first put it up MissWinter01. I would have predicted your dear friend giving this man an alibi (in this case in the form of a supporting story), would have known that you had a small window of time to report it in, before it occured to this man to bully and manipulate your friend into giving said alibi. And maybe, I could have told you things that would have encouraged you to report it sooner ... within that small window of time. Been there, felt the fear, then the shock, then the anger, then the betrayal.
I am so sorry. I don't know if it is of any help at the moment, but one thing I can tell you ... I know it for sure ... in her heart, where it counts, your friend hasn't really betrayed you. She is terrified. Not just for herself, and her child, but for you, her brother, her family, for everyone. She's in survival mode and (for the moment) doing what she thinks is safest. She's wrong, but she hasn't accepted that yet.
Sadly, it's not over, but you have done the right thing. You have to stay safe, keep your family safe, take a step back, deal with your own shock. (That last is so important, you can get support to deal with your feelings). There may yet come a time when you can help her.
I know you are name changing and moving away from this for now, MissWinter01, but if you need to talk, need help with getting support, or just want answers to questions, then feel free to PM me. If I can help, I will. 