No you haven't, I am well aware that people in different industries work different hours. I may never have been in paid employment as such, but I'm afraid the presumption that I do not have a 'job outside the home', is just that, a presumption and an incorrect one at that. Among other things, as an employer, I need to know the different rules and regulations, reading between the lines simply wouldn't wash in a court of law.
The farm workers or labourers we employ don't work 9 till 5, our cook doesn't work 9 till 5, our grooms and many more of our household staff work a variety of hours. The fact remains that if they are asked, on a regular basis to work above 48 hours per week, they have to sign an opt out.
However, the point made was about, guess what.... Catherine and as I presume she holds a 'normal' type job, the ordinary old 40 hour week would apply.