"No disciplinary measure of any type is appropriate."
Exactly this. Any replies from them after this, and you/she has to ask herself how important it is that she go back.
Right now they have no idea what to do (well, they do, but want to feel her out before they drop that on her). That's why they're asking her
what the appropriate disciplinary action should be. If it reasonably lines up with what they think is appropriate, then they'll (after careful deliberations) begrudgingly agree "but let's put this behind us and not let it happen again".
If they press back with "we have to do sOmEtHiNg", and/or if they won't commit to a disciplinary action, and you feel that you have to throw out the first 'offer', double down like Enoch suggests. Point out that she was suspended for six months without pay (which is more than enough to be considered a disciplinary measure), and that moving forward she will not only be fully reinstated in regards to tenure and curriculum development (and no physical 'shadow' or any requirement for her teaching programs to be subjected to any sort of pre-approval outside of normal parameters) but she will also be compensated with a 40% pay increase (start at 40%, whittle down to 25%).
They're asking because they want things to "just go back to the way things were before all this crazy covid stuff", but they also want to put 'something' on paper for future issues with both her and potentially other employees.
* leave the house out of the conversation, they don't care