Interesting Idea, but I'm not a fan.

If she weren't Luke and Leia's Mom, yes padme's death would have been a natural turning point. Instead what you might not realize is the turning point really is when Anakin loses his mother in episode 2, he hides his dark side well through the rest of the series while cheating the system by being married to padme. And it works fine till his feeling put him against the Jedi Order about killing palpy

The build up that Anakin who'd already lost his mother, at risk of losing his wife, to be the very force that leads to her demise, could have been better but I'm honestly not sure how to fix it more without getting more heavy handed.

I'd fix Padme dying, she should have just been like crazy aloof and depressed, show her holding her twins and not caring, or some nurse or doctor mentioning that padme hasn't even held her babies. Dying of a broken heart is a thing but it contradicts previous lore and I hated that, even if Anakins and Padme's tangential deaths blend beautifully.

If I were to rewrite Anakins story, make him a bit older in Phantom so the "He's too old" line makes a lot more sense and him and padme are closer in age. Have him deal with his dead mother in the same movie he officially turns to the darkside. I'd have him leave for love earlier in the series. Then lose his shit over his mom, Padme calms him down but then he starts having reoccurring nightmares about losing her and it just rapidly spirals out of control. Instead there's this drawn out spiral and it doesnt feel authentic.

If the jedi were worried about him being impulsive then the downward spiral should also have been impulsive.