I Became Cinderella's Stepsister Anastasia

In the dim light of dawn, Ann blinked her eyes open, disoriented and groggy. The last thing she remembered was slumping over her desk during yet another late-night overtime at the office. But this wasn't her cubicle. This wasn't even her world.
She sat up, her surroundings spinning. The room was adorned with gilded mirrors, delicate lace curtains, and an opulent vanity. The air smelled of roses and secrets. And then she saw her reflection-no longer the tired, bespectacled Ann, but a woman with flowing chestnut hair, porcelain skin, and eyes that held both curiosity and fear.
"Anastasia," a voice called from the hallway. "Are you awake, my dear?"
Anastasia? Who was Anastasia?