Renewal of vows
Couples renew their vows for very individual reasons. It may be a significant Anniversary or they may have been through a traumatic event such as a health scare.
The reasons are varied but the object is to confirm their love for each other with family and friends present. With the divorce rate so high, to stay together for a significant time is something to celebrate.
Even though there is no legality to the ceremony adding a blend of the original ceremony and things you have both treasured over the years makes a beautiful day. The addition of children and possibly grandchildren is a great idea.
The couple may wish to exchange rings or other pieces of jewellery and the ceremony could be written to include references to the time the couple have been together and their journey to now if they wished.