Aussie Andy,
As a regular flyer with the wife and kids I can highly recommend it and cannot help feeling that there is an air of OVERcautiousness in this thread.
You admit your level of experience is not that high and that you promised 10 hours P1 before taking the wife and kids. I admire the fact that you clearly thought about it and made your own parameters before taking them up.
Kids of seven years old do not just panic especially if they have been properly briefed on what to expect. Your wife will not be particularly interested in what YOU are doing either.She will enjoy the take-off, the landing and the view. Apart from that she will not be interested or impressed with anything else you are doing to keep the a/c in the sky so you'll have plenty of time to concentrate.
Meanwhile you will be giving your kids the experience of a lifetime. How often do we read in the flying magazines about how we should all take the time to take a child flying. Well if you cant take your own why bother taking someone elses.
A A, you have spent a lot of time and money on your licence, if you want to take them up then bloody well go. Surely the smiles on your girls faces will make the whole licence worthwhile doing.
PS. Don't forget to travel in separate cars to the flying club, it could be dangerous to all go together.