Conversation so far:
Who did Edmund Hillary marry?
Hillary married Louise Mary Rose.
What day did they marry on?
3 September 1953, soon after the ascent of Everest.
What did he say about it?
he admitted he was terrified of proposing to her and relied on her mother to propose on his behalf.
What are his childrens names?
They had three children: Peter (born 1954), Sarah (born 1955) and Belinda (1959-1975.

Question: What was so special about them?
Self-contained rewrite: What was so special about Edmund Hillary's children?