The baby, born earlier this week, was named after her paternal great grandmother but she will go by her middle name, reported Ace Showbiz.
"We're very excited to welcome Rebecca Klein Moore into the world. Both Mom and Klein are healthy," the Moore family said in a statement.
The couple's new daughter joins sisters Ella Kole, 4, and Kennedy Faye, two and half months.
"Her two older sisters helped with her first bath and are thrilled to have a little sister! We are blessed," the 'Small Town USA' crooner said.
"I would want to know, but my wife wanted to wait and she wins most battles. I've got all girls as of right now. I am sure I will have another one," Moore had said.