Ardern told Lucy that her kind words of support and encouragement had really helped her and praised her.
"I can tell from your letter that you are a kind and compassionate girl, Lucy, and I would just like to encourage you to keep spreading that kindness throughout your life," she wrote.
Ardern also said another thing we could do was show love to our Muslim community, and challenge anybody who is being mean based on somebody's religion, culture or race.