The Dress

David's Bridal does not allow you to return. All sales are final. They might do an exchange within 30 days but it depends on the store. It also depends on if the dress has already been ordered in your size.

My sister bought a new dress. She has her old dress at my parent's house and she will either sell it or donate it.

Most stores won't do anything, especially bridal salons that custom order your dress to be made. I'd stop looking if you've purchased a dress.