Well, that's one individual and it is up to her. Same as any worker in any workplace. You can't tell an individual not to do something because it affects other people, I am afraid.
This is a huge problem in lots of public service roles, that people are somehow not supposed to put themselves first so struggle on with physical and MH issues because of guilt. Before the pandemic this was a well known issue within the teaching profession who were cited as having some of the highest stress levels of any profession. Why this would have become less of an issue in general high stress times is beyond me. And it is more likely, actually, to impact your DC if they are being taught by a desperately unhappy teacher. It sounds to me like bustopher definitely does need to take some time away.
There is no doubt in my mind that the so called covid secure classrooms were pretty poor places to teach in, and be educated in form September to December. sadly, the government doesn't look interested in changing anything.
82% of teachers in a large survey last week said they had seem a fellow collegaue crying in the last term. 82%. That should worry people.