To only work very part time?

theres no 2 day contracts at my place of work for this very reason….I get where your colleagues are coming from

It's understandable you don't want to work more hours, as you need to prioritise home life right now. Presumably the company valued you and agreed the request in the circumstances. It was probably the right thing to do to support you but possibly the wrong thing from a business pov.

It sounds like you have quite a big job for low hours. 12 hours per week TTO ends up being more like 9/10 hours when averaged out across the year. At my work the minimum is 22.5 hours per week.

It's unprofessional for them to complain like that, especially as managers, and it's not your fault. However I can see why they are frustrated and unless the company takes on anyone else or comes down hard on the gossip, you may need to stay very thick skinned.

They're understaffed. That's their problem, not yours.
The work that doesn't happen when you are not paid to be there isn't your responsibility.

Is your long term plan to remain that part time? If so you need to hold your head high and work your hours but accept you are going to need a thick skin and will become a lot less relevant and part of the wider team. Do you line manage others too? I just can't see how that would work long term without disgruntled team members. Again not necessarily your issue as your request was approved but dropping to such low hours ok a long term basis may run the risk of making yourself redundant over time

It does sound like your management is horrendous, and everybody is (rightly) annoyed because of whoever is in charge.

As a poster said, you need a thick skin, because none of it is your fault or your doing, and bad management is making everyone's work life difficult.

Global head of accessibility?

It sounds like someone higher up in management signed off your request without consulting the day to day manager(s) and the team about the impact on workload. Tbh there are a lot of jobs where 12 hours a week is pretty pointless, by the time you've caught up on emails, had a few meetings you're off again with minimal work delivered. This isn't your fault. But it depends how thick skinned you are as the team will probably see it if you quit they will hire someone else full time and their workload will improve.

Wow. You should be proud of yourself for taking on that responsability. To go from 0 to 4 is tough, especially when there is trauma behind. Just ignore the assholes. You are doing something extremely valuable for these children and ofcourse you shouldn't take on more work than you can handle. They can hire someone else for 3 days a week and problem solved.

you shouldn't be give the same workload that you had when working full time either.

You were needed when you worked full-time, you are working less, the workload hasn't changed, they do need to employ someone else. It's really not difficult to find part-time employees, there are more request than jobs

Is this also termtime only?

It's not on that they are all gossiping about it, especially the managers, they shouldn't have agreed it if it wasn't going to work for the company, it's not your fault that they did and it's ? not working

What's the role? Is work time sensitive - can it wait until you return the following week or do others need to pick it up whilst you are off? Again, not your fault, but can see why they might be frustrated. However their frustration needs to be directed at the management.

We have a 0.5 whole time equivalent minimum, as anything less than that felt to be inefficient. But it's quite role dependent as to what is practical.

They're wrong to do it within ear shot of the OP! They do sound bitchy. They shouldn't have to pick up the slack but should complain directly to management at appropriate time.

I’d be inclined to talk to HR/ Senior Management about this . Managers should not be openly discussing this with junior staff - completely unprofessional bordering on bullying . Clearly your colleagues don’t understand the contract that has been drawn up between you & your employer. They need to go through the correct channels if they have an issue with their workload

If they stopped gossiping, they'd get more work done!!
I think you need to make notes of what is being said and if needs be, put in a formal complaint about the way you are being treated. It is not acceptable for you to be having to deal with this level of nastiness.

That's not helpful.

They don't sound "jealous and bitchy", they had a full-time working colleague that went from 2 days a week, school hours, and they have to pick up the workload, presumably without extra pay.

They very reasonably are complaining to management about that.

Not the OP's fault, not the OP's problem, but the colleagues are not wrong to complain.

Well that's a them problem 🤷
As long as you are doing your job within your contracted hours you need to just ignore them gossiping.