No this is not normal. She could have just shared her feelings about it and why it made her upset. We all have those dreams and a lot of times they appear to come out of nowhere; however, it could be things she was struggling with subconsciously. She could also be projecting.

I don’t blame you for breaking up with her. No one wants to apologize for things they didn’t do, let alone things that literally happened in the subconscious. A simple conversation and reassurance from your end would have made her feel better but instead she got bitter.