In Breaking Dawn, there is a huge controversy about Renesmee being an inmortal child. The Volturi believes that she is inmortal, but the Cullen's are trying to tell the Volturi she is not having witnesses who during a month saw how Renesmee grew being a half-human half-vampire beig. The Volturi come and are threatening to start a fight if they cannot come to a compromise. Renesmee shares her story with Aro to prove she is not inmortal. When Renesmee touches someone she can tell them the person whatever she wants.This is possible cause one of Nessie's powers (as Jacob named Renesmee) is the share of thoughts, the opposite of her father power.
In the end, The volturi leave the Cullen's and Edward and Bella live happily ever after.