"What is there to know?"
This train of thought right here is the entire problem even though no one wants to admit it. You say above that she wanted a better future and peace. Ok. Good motives. And then she magically achieves this. But when it comes to how no one but me is appearing to care.
What really makes me laugh is Madara has been really off to the side and people have been wondering about his motives, reasons and actions for like 10 chapters now. So in order to give Madara some exposition into why he feels the way he does and panel time Kishi invents this Kagura woman who ate the evil fruit and brought peace then the war again that is now crescendoing into ALL our problems and will probably never be expanded on again.
How she GOT the fruit or even knew what it did wasn't even explained very well if at all. She shouldn't have even had motivation to eat it according to Madara. This is a HUGE lynchpin and more storybuilding then we've seen in Naruto in a LONG time and she's glossed over as the baby momma. Women who are defined by their biological functions are not characters. PERIOD. That's Character Building 101.
I can't paint it any more plainly for you.
Well if Kishi decided to make this woman Kaguya into a man wouldn't it be the same problem?
Couldn't this hypothetical man have a child of his own with the same traits ( being born with chakra)?
The general idea is that someone decided to use the Juubi's power to end war but couldn't defeat the Juubi when it went after the humans. But her son surpassed her where she couldn't. I seriously don't see why her failure is considered sexist but the Hokage's failures aren't.
Honestly please explain it to me why her having a child is so negative and disrespectful for women.