Update ..
I've now spoken to both the teacher and year hea this morning.
I got defensiveness and heavy sighs from the teacher. She said the whole class are the problem and I could see how approachable a child would see this.
She said more... but essentially ended with of course DD can come and she's always happy to help.
I asked exactly what the piece of work was and could I get it in writing. To which I was told "NO". The students just needed to listen to her ... que rant on how nobody listens ... blah blah blah.
More specifics of the convo would be outting, but suffice to say she was utterly unprofessional. I don't know if she's having a breakdown .. but she went on about achieving good results with previous years and her being a competent teacher. Hmmmm.
I wished I didn't bother, but at least now I understand exactly how DD feels and I could with first hand experience explain to the HOY.
I decided to call the year head who was mortified, especially after I said DD refuses to stay on in 6th form... as she wants to do said subject at A level and can't risk having this teacher.
Concerns have been raised by others and it's being looked into, but HOY sounded very unhappy with the mimicking and how she seems to have cut off the avenue of students getting support from other teachers by shouting at them.
I didn't bring my governor role into it, but I was on the panel who interviewed this particular HOY, so she knows me ... or at least the name.
Usually when a number of different staff at work complain about a manager separately.... the issue is usually with that manager.
Yet they don't self reflect and wonder why so many in the team have raised a grievance. It's often the same issues as well. Unapproachable ... makes them feel small or stupid.
I often ask the manager why they think so msny have raised the same issue ... and the response is " they don't like me ..." I'm not a pushover" ... all really excuses fit their poor management style.
I see the same thing here with the teacher ... but thankfully it's being dealt with now and I've been told not to hesitate if I have further concerns.
Sadly people like this totally lack any self awareness. All the students can't be the problem.
Will respond to specific questions later if possible.