My Catholic brother and his Christian wife were married in a non-denominational Christian church a few years ago. They have recently been asked to be Godparents of a close friend’s child (the family is Catholic). In order for them to do so, they had to renew their vows in the Catholic church in order for the church to recognize their marriage and allow them as the Godparents. quote]
this is not simply a renewal of wedding vows, it is a convalidation, that is, having their marriage recognized as valid by the Catholic Church. Explain to your sister-in-law that your brother is bound by Catholic canon law to marry in accordance with the laws of the Church. Since he did not seek a dispensation to marry a non-Catholic in a non-Catholic venue, he is not married. Since she chose to marry a Catholic, she has to live with the fact that, if he now wishes to claim the privileges of being Catholic such as serving as a godparent (which only he, not his wife, can do), he must comply with Catholic laws regarding godparents–they must be fully initiated Catholics and if married, it must be valid. She can however, once this is done, stand up with him as Christian witness. Once the marriage is convalidated, if she is baptized, it will also become sacramental. You may want to explain the meaning and importance of that fact as well.