To not do extra at work..

[purplefurby]

I have 2 young kids so only do 2 days. When I started I said if given a decent amount of notice I could possibly cover holidays etc the odd day. Smallest DD is only 2.
They don't employ enough staff to cover unforeseen circumstances.
With eldest dc being off school we've had a few lie ins over Christmas.

3 times I've woken up lately to missed calls at 7am and texts asking if I can cover sickness. They're fine when I say no.. but I'm the only one with little kids. It's getting annoying. They know I don't have childcare.

AIBU to say no all the time?

If they are fine when you say no then just keep saying no but don't assume people without kids are automatically more available at short notice than you.

You've unfortunately set an expectation that you're available - I think you need to have a chat with your manager to clarify what this means - particularly that you need [x] notice and are not available same-day.

You can say no but you already told them you might get able to cover, if you can't just tell them not to call you.

Well of course it's reasonable to say no.

What's stopping you having a chat with your manager about this? Are you worried it will look bad?

Given that they're always going to want cover for holidays and half terms which you can't do, I think I would say 'contract only'. But otherwise just keep saying no.

Tell them you can't cover at short notice. However there's no reason for people without children to be expected to cover at short notice either. They might have their own plans and commitments.