Why Does Padme Pretend to Be a Handmaiden?

Serving as a handmaiden in the Royal House of Naboo, Sabé was duty-bound to protect Queen Padmé Amidala—the elected ruler of the people of Naboo—against any threat. As such, she impersonated Amidala during the Invasion of Naboo in order to keep her safe from the Trade Federation.

Is Padmé the Queen or handmaiden?

Near the end of Star Wars: Episode I: The Phantom Menace, Queen Amidala reveals that she's also Padme, one of the Queen's handmaidens. She would travel freely as Padme, and have Sabe, one of her handmaidens, be a decoy Queen. The Queen of Naboo is an elected office.

Who is Padme Amidala's decoy?

Sabé is the most important of Queen Amidala's royal retinue of handmaidens. During crisis situations, Sabé and Amidala switch roles. Sabé becomes a decoy, disguised as the Queen, while Amidala adopts a simple gown of a handmaiden, and goes by her less formal name of Padmé Naberrie.