The Switch:Anna and Stephanie

Anna has been married for three years without bearing a child. Kathryn Anna's step mother in law decides to make Anna's husband, Sebastian, remarry. Anna has no power to fight but a call changes everything. A woman "Stephanie" offers to help her and to her surprise they are identical. Is she her clone or twin? Will the Adams family realize that she is not Anna? Is Stephanie trustworthy? Why does she offer to help Anna?