Complex sentence: He is married to German-born illustrator Kerstin Konietzka-Knight, and they have two children; she and the first child, a son, appear as characters in The K Chronicles "and" The Knight Life.
Split into simpler sentences: He is married to German-born illustrator Kerstin Konietzka-Knight. Both wife and son appear as characters in The K Chronicles "and" The Knight Life.