The excerpt from The Awakening that best illustrates the idea that Edna is losing control of her life is this one:
She answered her husband with friendly evasiveness,—not with any fixed design to mislead him, only because all sense of reality had gone out of her life; she had abandoned herself to Fate, and awaited the consequences with indifference.
You can see it says that she abandoned herself to Fate, which means that she doesn't control anything that happens to her anymore.
