Conversation so far:
How many times did Harriet Tubman get married?
Harriet Tubman was married twice.
When did she get married to John Tubman?
Around 1844, Harriet Tubman married a free black man named John Tubman.
How many children did Harriet Tubman and John Tubman have?
Harriet Tubman had one adopted child, Gertie.

Question: How did they meet?
Self-contained rewrite: How did Harriet Tubman and John Tubman meet?