"But she ran into problems when she tried to ask people to come in for three days, and suggested that teachers could also use their time to prepare powerpoint presentations about their performance in the year so that they could have their annual appraisals."
So at the height of a pandemic, when most Heads and employers were trying to minimise the number of people in their school/place of work and encouraging as many staff as possible to wfh, she asked hers to come in for a third day to create PowerPoint presentations about their performance over the past academic year?
They were already coming in for two days - one day to provide childcare on a rota, one day to create homelearning materials.
I would bet anything that they would have happily gone in for a third day if it was to teach, provide childcare or do something that couldn't be done from home.
But she was asking staff to send their kids to childcare, maybe not even their usual school or childcare provision if that was closed, to produce a PowerPoint about their performance? I'm not surprised they said they'd rather do it from home tbh.
She handed her notice in in January and leaves in July. It sounds like a last vindictive slap to those who stood up to her. Of course her comments were unprofessional, showed lack of leadership on her part, brought her school into disrepute and would have allowed parents and the local community to identify the teachers in question.