1. Never, ever allow a child to roam the cabin unsupervised. There has been at least one sad case of a child falling out the baggage door.
2. Cross-wind landings can be hard on a young child's tummy. I have twice had to do a clean up after landing as you there's nothing you can do for the child when he gets sick in the flare.

As others have mentioned, a proper car seat and ear protection are required.

Flying with a 7 yr old
 

:ok: Giving children of any age a trip in a light aircraft is a great way to provide the world with future pilots! Some are put off straight away, but I believe that many will have the seed sown in their minds for a future career. My son first flew with me at the age of eighteen months, continued the experience on through childhood, I bought him a flying lesson at the local club for his thirteenth birthday, he now flies Tornados for a living.

Thanks everyone for your advise.

I'm pleased to report that she loved it and we even had to take a detour on the way home so that she could see her house & school.

A couple of other things for anyone considering it:

She was told that she can't go infront of the wings unless she's been invited by me
We agreed that when I put my hand up in the middle of the ac, everyone stops yapping.

The only problem is: She wants to know where we're going next week

Nice one... Did the mum enjoy it too?
In 18+ yrs of taking people up for flights I've never had anyone who hasn't wanted to go up again. I think that fear of the unknown before the flight worries most people. The actual flight is a pleasant surprise.

Next time ask for permssion to do a steep turn. My daughters love them and they also like it when I pull the nose up and then push it down...probably +1.5G and around 0 G.
They call it an 'up and downy' as in " Dad, can we do some up and downies?".

I also give them an old map with the route marked and a chinagraph pencil to mark things off. Also giving them a camera and responsibility for recording the trip. They enjoy it more when they are involved, even if they are just duplicating whatever you are doing.