I have always worked ft since having dc - I honestly think it's easier than doing 80% of the job for 60% of the money...
The Pay & Conditions are quite clear re: pt teachers & parents' evenings. My place always has them on a Thursday, tries to jig things so that pt-ers work on Thursday, & pays people/tells them not to bother if they don't.
Tbh, if I have something to discuss with a parent I wouldn't wait till parents' evening - I'd be on the phone or writing to them.
Theoretically I have 60 sets of parents to see in 2 hours next week (core subject - English). OK, that's unusual - I've got 2 classes in this year group; usually it'd be 30 kids & the actual uptake more like 20. When you've got 2 minutes per child, it does become nonsensical.
I've missed one parents' evening in 10 years (caused by dh booking uncancellable work stuff t'other end of the country without consulting me, the arse), rang the 3 parents affected, had an unpleasant conversation with the Head about it...posted on AIBU here & got a right virtual kicking!
Anyway, my argument is: if a teacher's pt (or for that matter ill or has another emergency), the sky won't fall in if parents know they won't see her on a given parents' evening - she can ring them or arrange another time to talk face to face. It's unreasonable to expect anyone to spend the evening of a day in which they don't work (or work in that particular job) doing a parents' evening.
It's not about professionalism at all, if we take 'professionalism' to mean 'keeping the students & parents informed' as opposed to 'martyring oneself in an inefficient manner'.
No disrespect to twinset - if her MO works for her then good for her - but it isn't an obligation & certainly shouldn't be an expectation.