Here's the thing OP.
After all this is over, a lot of people are going to be reassessing their relationships.
Believe it or not, people are going to remember their "friends" who boasted about stockpiling 200 loo rolls, the work colleagues who took the piss about home working and yes, the customers of the self employed who despite being lucky enough to still earn a wage decided to renege on their contracts to their financial benefit.
You seem to be of a mindset that your childminder will be eligible for govt funding. She won't because she is still working - providing essential support for key workers and as such is one herself.
She's stepping up to the mark here and even offering you a very generous discount.
Even if she wasn't working, again you misunderstand what she'd be eligible for. The govt have offered 80% of profits not revenue.
So for your £1000 a month, she wouldn't get £800.
Most businesses are lucky to operate at a profit of 30%.
Therefore she'd get 80% of £300 i.e. £240 and that's gross not net so after income tax potentially even less.
In the meantime you are wfh with full pay, whilst being disgruntled at the prospect of your childminder of over 2 years facing a massive drop in income regardless of whether she continues to work or not.
We all have a choice here; to do what's right or to be an arsehole.
That's the choice you are making right now - make no mistake about it.
Remember that, when you refuse to pay and we will look forward to your posts in the future where you bemoan the fact your child no longer has a place and you are (like many other CF parents) trying to find childcare assuming childminders don't talk to each other and will give a heads up on whose priority was saving money (despite unlike many still having the luxury of employment) rather than supporting a key worker.
So justify it all you like OP and celebrate the other posters agreeing with you, but this will come to an end and those of your ilk will find that people will remember your behaviour.