Sorry, this is an easy one: The marriage contract is “to death do we part.” She had the children either as a single woman, in which case the children are bastards, or as a married woman, in which case the children are the children of her husband.
As for Mormons, whose marriages continue eternally, now that would be a bit tougher; but, just a bit. Since, by the non-establishment clause of the 1st Amendment, the Congress may not establish a church, Mormon belief about eternal marriage is not a federal concern.
Some religions are more equal than others, muslims are exempt from ObamaCare...