to feel annoyed that colleague gets better treatment

[user9208291]

I work in a job where we work 9-6 Monday to Friday and alternate Saturdays ( with another day off in the week). A colleague recently returned from sickness and did a phased return of 9-1 for the duration of the phased return (5 weeks).
She has been back nearly 3 months and decides on the day what time she will be working till some days 2pm some days 3pm. She never does a Saturday.
AIBU to think this is unfair for the rest of the team that she gets to pick and choose her rota?

I find this thread quite intriguing as I got slaughtered on here for objecting to my workplace permitting all the parents to top up 50% of their working hours for over a year during lockdowns, with everyone else picking up the extra work for no additional pay. It made me seriously unwell in my own right (I'm mental health disabled).

I'll give you the advice I wish I'd got, OP - it's perfectly right that your workplace is making reasonable adjustments for your colleague. However, they shouldn't be doing that by using you as a work horse, particularly when they don't necessarily have any idea whether you have health issues that could be exacerbated by this. At the very least, you should be being paid extra for this. Raise this with your boss and if you have a union, speak to them.

TBF it would be easier on the staff if they knew in advance what time the member of staff was working to - like they did in the phased return

But it sounds like they are being rotaed on till later and then finishing early due to their health - whereas if you know your colleague is finishing at 1pm that day at least you know and can staff appropriately