Conversation so far:
Did Willie Nelson get married?
Willie Nelson has been married four times and has seven children.
Who was Willie Nelson married to?
Willie Nelson's first marriage was to Martha Matthews.
When were Willie Nelson and Martha Matthews married?
1952 to 1962
Who was Willie Nelson's second wife?
Willie Nelson's next marriage was to Shirley Collie.

Question: When were they married?
Self-contained rewrite: When were Willie Nelson and Shirley Collie married?