What effects does a declaration of invalidity have?
In civil law, none whatever. All such matters as the custody and support of children, property settlement, alimony, etc. were determined by the divorce court and are unaffected. Even in the eyes of the Church, such a decision does not deny whatever human reality was present, and certainly does not question the good-faith intentions of the parties (except in those rare cases where that is the alleged ground of nullity). In no case does it affect the status of children; these always remain legitimate in church law. The principal effect is that the parties, being free of that bond, are able to remarry in the Church if they wish.