Being on your computer is completely out of order and you should not stand for that.
Otherwise, I would say they did a halfway decent amount of stuff. Had they not gone on FB, I think they could have gotten the bathroom, as well.
Laundry and dishes will eat up a lot of time. I don't do them because few people want to pay enough extra for me to make their home sparkle and then mess with their stuff. If someone were to pay me for an extra hour's worth of work, I suppose I would do it. Very few people want to, though.
£10 an hour is a reasonable rate for two hours of straight cleaning, although I charge significantly more. Charging more means I have to be absolutely on my A-game.
I do carry my phone with me and I will answer it (in another room/out of earshot) if it's a potential client or the school. I get alerts for Twitter and email and I may look to see what it is, but I don't reply to things (unless it's something necessary.)
I would never, ever, in a million years, use the client's computer. I won't even turn on the TV or radio. Sometimes, if I'm there a while, I may plug my phone charger in and leave it on a kitchen counter so that my phone will stay charged. I also don't help myself to their food (although there have been a couple of clients who positively beg me to do so if I'm there alone and then I might have a biscuit if I'm there a long time. Only if I've been very strongly encouraged to do so.) I will have a drink of tap water from a glass, wash the glass, and put it away. I will use the toilet. But, other than that, I consider everything their personal property, never to be touched.