Her father wrote that, so I would assume they are a Christian family.
The girl’s funeral was in a United Methodist church, which in itself, doesn’t tell much. From their “What we Believe” page: “We believe that Dallas doesn’t necessarily need more card-carrying Christians; what Dallas needs are more people who are living like Jesus.”
The church itself apparently operates as a branch of the very prominent Highland Park United Methodist Church (Jerry Jones, George W. Bush, and Dick Cheney are current or former members of HPUMC).