At that time, in their culture, that was traditional. She forsook her parent's name, and took her husband's name. The taking of the new name, reflected a change in life, and change in status and a change in priorities. She was no longer a single woman, she was married. If her lifestyle did not change from that day forward, she would have been ostracized by her community.
Few societies encourage their married women to live in the same way as they did before they married.
She would have had a ceremony, but not a new life, and boy would my father have been . . . If you take the name of God, at a ceremony, and tell the world that you are now part of the 'bride of Christ' as the church is called, yet you do not live like a 'bride of Christ', you have taken His name in vain, and you will not be considered guiltless. Live with Jesus as if you are committed to Him for life, not as if He is a friend. A spouse is supposed to be an intimate friend, companion, confidant, friend and a lifetime commitment. To treat Jesus as anything less than that, is to take His name in vain.