it seems there was miscommunication between you and your friend, about weather you were able to say it was her or not but it does make sense that she's upset as she assumed you wouldn't say anything. Although, I do believe it isn't fair that she's posting things related to the situation without letting you know that what you did was wrong. The best optio you have if you want to amend your relationship with her is to talk to her about it :) friendship always have their ups and downs, and we learn bout one another such as boundaries and what's expected from one another through the way we communicate. Hope this helps somehow!