I have a site full of game ideas
www.mes-english.com but if you know what you're going to teach, you can always ask in the games forum here at eslHQ or search.
As for content, you should certainly follow a curriculum. Like Sue said, you can follow what she's doing at school or start with something that's more speaking oriented. There are a lot of great series out there for children. The most important thing is to supplement and add in what the child needs. Don't expect to just do a page a day and move on. That's probably what they are doing at school and what the parents don't want.
I would assume they want you to start with more basic skills and help their daughter to speak and enjoy speaking. The best way to do that is to keep it simple and doable in the beginning. Build the child's confidence, encourage her, reward her, and show her that you're there to help. Then in time, you'll see her trying on her own and trying to impress you with what she can do.
Happy teaching!