I'm wondering if you can give me some advice about some problems I'm having with my cleaner at the moment. I really don’t know how to sort it out without causing upset.
I realise that this is probably the opposite problem that most people have, but my cleaner is supposed to clean the house for a set number of hours each week and is staying for far longer than I am paying her for- often staying for up to an hour or more over the time she is paid for. I dislike this because it effectively means that her hourly rate becomes lower, which I am very uncomfortable with. Also, if I am at home when she comes it's a bit difficult because it means I'm stuck in one room for longer in order to keep out of her way (she has previously spoken to me for quite some time about personal problems which, whilst I am sympathetic, I was finding myself getting more drawn into her personal life more than I felt comfortable with so I have consciously tried to take a step back).
I have spoken to her a number of times in person when I am there, and also by leaving notes, to ask her not to stay longer than the agreed number of hours. E.g. on a few occasions I have gone to whichever room she’s in and (nicely and with a big smile) reminded her that she's been here for X amount of time and to make sure that she heads off soon. I understand that on occasion she may want to stay for an extra five minutes or so to finish a particular job off so I have never done this at the exact point it's time for her to leave; I've always waited at least 15 mins after the time she's due to finish before doing this. She'll often still stay for quite a bit longer.
I’ve made it clear several times that I want her to leave after the set number of hours, regardless of whether she's done all of the usual cleaning jobs. I've suggested that she just clean some of the (infrequently used, so don't get very dirty) rooms every other week or stop cleaning some rooms altogether to reduce her workload to make it manageable in the set number of hours. I don't really know what else to do.
To be honest, I can't understand why she is staying for so long in the first place. I used to clean for a living myself so I do feel I have a realistic idea of how long it takes to clean the rooms. Sometimes she will take it upon herself to start cleaning rooms that she's never been supposed to clean. I have found this irritating and, at times, intrusive e.g. I once found that she'd been in the study and tidied away all of my private paperwork, including bank statements. She has never been due to clean that room (for the very reason that it contains private paperwork) and had never done so previously. The same thing happened with another room and I kept leaving notes saying please do not clean that room, but she kept doing so. In the end I had to leave quite a blunt note saying please do not ever go in that room at all. She replied to say that she'd only been doing a quick tidy in there, which was missing the point but has at least stopped cleaning that room since then.
If I don't already sound horrible and critical, I also feel like she's spending time doing unnecessary tasks e.g. going in my husband's (closed) chest of drawers and folding all the socks and underwear in there 
, re-arranging throws that are already folded neatly, artfully arranging magazines that were in a tidy pile so that they are fanned out etc. Yet sometimes (not always) bits of the cleaning will have been missed e.g. parts of the worktop or floor won't have been cleaned.
I suppose what I'm wondering is how I can politely make sure that she stops staying for longer than she is supposed to, and isn't wasting time faffing about on jobs that look pretty but aren't actually cleaning.