Ah, it's fine, hunker. Honestly
It's just that, from my perspective, it sounds like a lot of middle-class women talking about their cleaners as though they were fairly useful sub-humans
If you can afford a cleaner, you should get one. I do agree with other posts that two hours is enough, though. Not because they might slack, as was suggested, but because it's pretty boring, labour intensive work ... and two hours is enough without a break.
Initially, I should ask her if she wouldn't mind wiping the skirting boards and doors down; the places that accumulate dust but which don't necessarily loom very large on your daily schedule. After that, the world's your oyster!
With two to four hours a week, you will start to notice a real difference to your home.
With regards to tidying mess, it's a difficult call. I would love to tidy mess, but what if something goes missing? I shall be the one, perhaps, to blame.
And with regard to recruiting, I think you should stick a notice in the Post Office window, personally. That way, you can 'interview' a few people, find out whether you like the sound of them on the telephone, etc.
You'll feel much for obliged if you use an agency, and you'll pay through the nose. It's really important that you like your cleaner, and she likes you, so the relationship is more rewarding if you know that she's just a mum, like you, who's trying to earn a few bob while her children are young.
Anyway, I'm rambling, but I'd be happy to discuss it with you in more detail later.