LOL! Good Luck. I would keep it very basic. More than likely, they don’t have a clue how to get the photos off the camera, so you definatly should touch on that. Stay away from things like lighting and shutter speeds. Talk about how to use a camera and give them suggestions on how to handle movement in digital photographs…which is not easy on digital camera, unless you know something about digital photography. Photos of Grandchildren would probably be a big topic to discuss.
You will definatly need to discuss the lingo. The need to know words like megapixel and such. More than likely they are not trying to become millionaires with photography, so teach them how to take pictures of the things they anticipate taking pictures of.