I honestly think she's trying to save face because she knows that you're not into her as much. I say that as a girl. I hope she unblocks you though and your friendship can work out. I wouldn't expect anything, or try to force it. She may find it easier to distance herself. Sorry that this happened. You were just trying to be nice.

To be honest I think deep down she should know she initiated. Maybe she's trying to save face. But if she truly doesn't remember then that's a bad situation. Either way I feel for you. Don't feel like you did anything wrong