I just don't buy Padme's motive for killing herself. Yeah, it was a bitch, but no one else decided to roll over and die. She had kids and friends to help her fight back. She even tells Obi-wan that "there's still good in him." which indicates:
1. She still believes he can be redeemed.
2. She somehow knows he survived or Obi-Wan never told her he (seemingly) killed him.
After fighting a seemingly hopeless battle to save her planet in Episode 1 are we supposed to believe that she is willing to just give up and die because Anikin turned evil? It's not like she didn't see the dark side in him (He wiped out the sand village), so how much of a shock could it have been?
Imo, she has the wrong reaction entirely, especially given her characterization up until then: imo she should've been pissed, not all weepy. That would've been a more natural reaction. Obi-Wan sure was.
Her death was another 'Lucas Plot Point' on the Lucus checklist of plot to be stuffed between the battles. It's just another symptom of Lucas treating the Effects as the main point and using a plot basically as filler between explosions.
You hit the nail on the head. I think GL wussed out by having Anakin not kill Padme flat out, inflicting a mortal wound with force lightning or a lightsaber stab, and she holds on just long enough to have the children.