Complex sentence: He married three times and had three children: a daughter named Kirsten from his first marriage with Karen Rigmor Larsen, and two sons with his second wife Ulla Meyer, also a tennis player and Danish champion.
Split into simpler sentences: He married three times and had three children, a daughter named Kirsten from his first marriage with Karen Rigmor Larsen. He had two sons with his second wife Ulla Meyer also a tennis player and Danish champion.