Because this Christian woman knows that the only unforgivable sin is to deny the Holy Spirit. Unlike fake religions which allow one to lie if the situation calls for it, she understands that either she profess faith or deny faith, and her eternity in heaven will depend on her choice.
God bless this woman as she is a living example to us all!
You believe that if she lied to scum in order to save her life that she would be denied eternity in heaven? God would know the truth when she spoke her lie and would never punish her for that.
He would know what was in her heart.