we are Pennsylvania Dutch, which is very close to being German, and we loved the food and found much of it authentic, the pork schnitzel, the warm potato salad, the sausages, the black forest cake, etc.
We thought the food was very good, but it isn't a place we will visit every year because it resembles the food at home.
For children, they did have little hot dogs and mac & cheese but I did see children bring food into the restaurant so their parents could eat there - believe me, Disney does not frown upon any of that (when our children were younger we did the same thing)