Conversation so far:
WasPrince Bernhard of Lippe-Biesterfeld married?
Prince Bernhard of Lippe-Biesterfeld married Wilhelmina Helena Pauline Maria.
Who was Prince Bernhard of Lippe-Biesterfeld married to?
Prince Bernhard of Lippe-Biesterfeld was married to Princess Juliana
Did Prince Bernhard of Lippe-Biesterfeld and Princess Juliana any children?
Prince Bernhard of Lippe-Biesterfeld and Princess Juliana had four children
Did either Prince Bernhard of Lippe-Biesterfeld or Princess Juliana have children outside of the marriage?
Prince Bernhard of Lippe-Biesterfeld had two natural, or illegitimate daughters

Question: Were they conceived before his marriage to Princess Juliana?
Self-contained rewrite: Were Prince Bernhard of Lippe-Biesterfeld two natural or illegitimate daughters conceived before his marriage to Princess Juliana?