Conversation so far:
What is the name of Karlheinz Stockhausen's wife ?
Doris Andreae (m. 1951; div. 1965) and Mary Bauermeister (m. 1967; div. 1972)
When was Karlheinz Stockhausen married to Doris Andreae ?
On 29 December 1951, in Hamburg, Karlheinz Stockhausen married Doris Andreae.

Question: How many children did they have together ?
Self-contained rewrite: How many children did Karlheinz Stockhausen and Doris Andreae have together ?