Character Analysis
Domestic Bliss?
Here's the sad thing about Revenge of the Sith. No, it's not that Padmé dies. It's that she doesn't really live in this film.
Although she plays a much larger role in the previous films of the trilogy, Padmé is little more than a plot device in Revenge of the Sith. Sure, she's Anakin's one true love and the mother of his unborn progeny, but there is very little development for her as a character. Mostly, her purpose is to be the reason for Anakin's descent to the dark side.
In Revenge of the Sith, Padmé is basically the generic loyal, infatuated, simplistic spouse, which is frankly … disappointing. In The Phantom Menace, Padmé was the queen of Naboo, a politician negotiating peace for her world (and fighting for it, too) while flanked by various senior officials. She was important enough to need a body double in order to thwart various assassination attempts.
In Attack of the Clones,she had ended her term as queen and was now the senator representing Naboo in the Republic. She led a faction opposed to the people who wanted to create the clone army, for Pete's sake. This was no simpering, pregnant-and-barefoot-in-the-kitchen wife character—so why is that all she is in Revenge of the Sith?
Well, because her good scenes got cut. There are several deleted scenes (actually, a deleted plotline) in which Padmé and a number of senators organize themselves into the Alliance to Restore the Republic, a group of like-minded individuals who agree that Palpatine has overstepped his bounds and amassed too much individual power. (Source)
They don't want to start a war but want to see if there is anything to do to conserve the Republic and put a halt to Palpatine's coup. She actually hints at this thought process at one point while talking to Anakin, but he recoils so quickly that she retracts her statement and recedes into subservience once more.
The one time we see her actually act like a senator is in the scene in which Palpatine announces his new role as Emperor. She reacts with disbelief and dismay and famously says:
PADMÉ: So, this is how liberty dies. To thunderous applause.
Unfortunately, though, because the majority of those scenes got cut, we only see Padmé as the object upon whom Anakin becomes fixated. She is the reason why he turns to the dark side, and then her death cements his newfound alliance.
But … Why Did She Die?
By the end of Revenge of the Sith, it seems like her character has been so diminished in scope and importance that George Lucas didn't even feel the need to provide a legitimate death for her.
As she's delivering her twins, the medical droid explains that there is no medical reason for her to die, but they're losing her regardless. This has become a divisive moment for Star Wars fans because there are two theories that explain her death—and each side has some pretty rabid proponents.
Theory #1: George Lucas is a terrible writer, and he couldn't think of anything for her to die from. Or, she died from a broken heart, which is a tired Hollywood trope at best, and gag-inducing at worst.
Theory #2: this one is actually really interesting. This theory posits that because droids cannot feel the Force, they would not be able to diagnose the fact that Padmé is dying because of something (or someone) severing her connection to and draining her of the living Force.
That someone is Darth Sidious, who's trying to save his precious new apprentice by channeling Padmé's force into her dying husband. How else would he have known that she was dead, when she died worlds away in a secret location? (Source)