Quotes from Roy Mason

The Family of God includes all of the children of God in heaven and on earth. In Ephesians 3:15, Paul speaks of the whole family in heaven and on earth. This family includes all believers. "Ye are all the children of God by faith in Christ Jesus." (Galatians. 3:26) All believers are God's children.

The Kingdom of God includes all of the saved on earth at any given time.

So the family of God includes all of the saved of all the ages, whether in heaven or on earth. The kingdom of God includes that part of the family of God who are on earth now.