Maybe reason with her along these lines:
Are we made in God's image?
If so then according to Romans 2:21-22 it says this:
"do you, however, the one teaching someone else, not teach yourself? You, the one preaching “Do not steal,” do you steal? You, the one saying “Do not commit adultery,” do you commit adultery? You, the one expressing abhorrence of the idols, do you rob temples?"
So along these same lines of reasoning couldn't you say, you the one saying do not murder, do you murder?
Then point out Romans 12:17 " Return evil for evil to no one. Provide fine things in the sight of all men."
So does God not hold himself to the same standards he expects of others?