My supervisor at work made a mistake and I need advice on how to handle it

It’s kind of complex to fully explain. My supervisor didn’t tell me and my coworker that we had a meeting to attend today so we were completely unprepared and surprised when we got called into a meeting. Some other coworkers in the meeting did know about it and were completely prepared with detailed notes. In addition she was supposed to call a replacement for us so that we could attend the meeting while our duties were still being done and she didn’t do that either. This led to some last moment scrambling and band aid solutions to make sure all our bases were covered. But we were quite flustered.

Everyone in the meeting knew it was her mistake but how or why this occurred is still a wonder to me. I figured she would at least come to me later and explain to us wtf happened since it was kind of embarrassing for us. She never did. I think it’s important to say something about it since communication in this workplace ever since she has taken over has been really bad.

How should I approach this?
And no, I don’t think she’s trying to sabotage us. She’s just new and inexperienced.