This is my take too. Bad situation, and stressful middle part, but reasonably good resolution. How you and your daughter move forward is a good way to refocus your pent up frustration.

I hope the vent helped! It sounds like part of what’s bothering you is that you expected better. That’s reasonable, but I hope you regain some confidence in her school and the teachers. The apology from the teacher is direct, takes responsibility, and restores the grade. That’s pretty good!

They can’t undo the stress from the miscommunication, and they can’t promise it won’t happen again, but the systems for catching these kinds of mistakes seemed to have worked. That’s pretty good too!

(For context only, I’ll add that I have two kids who did online public school during the worst of the pandemic, and are back in person now. We’ve had problems similar to this one in every format, almost every year. So, that doesn’t change anything that you experienced, but I have some idea of how bad it feels, and what it takes to move on. You can do it!!)