Tell her, just once, not to do your washing anymore. If she continues, take back her key. If she refuses to give you her key, change your locks.
Yes, she will complain. But she's complaining anyway, by saying how untidy you are and so on. She's not trying to help, she's criticising you and making it impossible for you to respond without it turning into a show of how unreasonable you're being--when you're not being unreasonable at all.
When she complains, refuse to engage. If you don't engage, she's got nothing to kick off against. Say, perhaps, "We can do our own washing, thanks," and change the subject. If she won't drop it, ask her to leave. Because you really don't need the stress of this toxic behaviour from your mother.
It will be awful for a while. But it's not good now, is it? And I bet she's not just controlling about the washing: I bet she does other stuff you've asked her not to, too.
Once you've dealt with the washing situation other things might well come up that you'd not noticed before. AGain, say what you want to happen then refuse to engage in discussions. Either things will improve or they'll stay as they are, with her complaining and criticising. But at least you'll have tried to make things better. And once you learn to stop engaging with the complaints and criticisms your life will be magically better, even if she doesn't stop.