Assuming that there were no obvious impediments to their marriage (e.g., previous marriage), no. The Church presumes non-Catholic marriages to be valid. If both parties are baptized, the Church presumes the marriages of non-Catholic Christians to be sacramental. Although it is in no way required, the couple may renew their vows and have their marriage blessed by a priest, if they wish. If they are interested in that, they should speak to their pastor about arranging it.
