You could be sued hy her for half the wedding costs and she may prevail.  This is similar to contract law and exceptions to contract law, wherein the performance wedding occurred. She relied to her detriment paying for the wedding and wed but shortly thereafter, separated.While she essentially decided to divorce, it may be in your best interest to contribute but you are also entitled to half the gifts.  You may suggest returning the gifts you can and having the stores give each of you half of the worth of the gift on a gift card.