Tanzania is a superb family destination, provided the trip is built for the children rather than adapted for them afterwards. That means shorter driving legs, camps with family rooms or adjoining tents, a pool for the middle of the day, and a guide who is happy to explain dung beetles as enthusiastically as lions.
We usually recommend a private vehicle for families — being able to turn back when a small person has had enough is worth a great deal. Ngorongoro Crater and Tarangire tend to work better than long Serengeti transects for younger children, because sightings come quickly and the drives are short.
Most camps welcome children from around six years old, some from twelve, and a few not at all; walking safaris and balloon flights carry their own minimum ages. We check every property against the ages of your children before we quote, so nothing has to be unpicked later.