Rhema produces understanding. It is this understanding that will rule all nations with a rod of iron. The faith conceived by the woman will turn people to Christ and cause them to become sons of God. These are the children who are added and are the rest of the woman's offspring. Faith will move mountains.
Mountains are symbolic of world governments.
Iron stands for the strength of a kingdom. And as the toes of the feet were partly of iron and partly of clay, so the kingdom shall be partly strong and partly fragile. God uses the strength of faith to establish His everlasting Kingdom. She remains in the wilderness for three and a half years. During her absence, the beast was given authority to rule for three and a half years.