There's something odd in the wording in Genesis 12.
In verse 13, Abram tells Sarai, "say you are my sister."
In verse 19, Pharaoh says to Abram, "why did YOU say she was your sister?"
Pharaoh makes it clear that Abram is the one who said it. But did Sarai say anything? Perhaps she said nothing? Maybe she told the truth? It's unclear.