Welcome Mark!
For non hunting family activities it really depends upon what your family enjoys.. I'm more familiar with the EC where options abound. Not sure what is up in that area your going to other than good hunting.
If you have the budget and time here's a thought;
An associate of mine who hunted that area took the Rovos Rail from Pretoria to Cape town and had the most dangerous experience of his whole trip while on board.... He spilled hot coffee on himself.
They are an older couple but very active and enjoyed it immensely. Lots of stuff in the Cape Town area including bus tours of the city, Table Mountain, great beaches, and you can rent a car and drive out the Cape of good Hope.
But talk to your outfitter as well...
Have you seen what he offers? The elephant back safari looks interesting? Hot air balloon?
http://www.africamaximum.com/downloads/Activities_Tours.pdf
On our first trip my wife made a list of all the animals, birds, even plants and insects she saw... If it is your first time, there are so many new things it overwhelms your senses. By the end of day one she had 20 animals on her list... A lot of them from the drive into camp the evening before. Speaking of which, be sure to get your PH to take you and the family out on a night drive with a spot light. Or 2 or 3, even take a couple real good flash lights with... If you shop around you can get pretty decent LED lights for $5-10 and let each kid use one... Then make gifts of them to the trackers and camp staff.
If you have more time than money, rent a car and do a self guided tour around the area or even pop over to Kruger or some other parks that rent out bungalows reasonably. Read my Zimbabwe report on our tour of Kruger or ask and I'll provide more info but it was about $90/night plus some night game drives and the car rental and food...