So is this what happen?

[Devauzamaki]

Kaguya ate the fruit,and somehow after awhile became what we know as the jubi.
Her son Hagaromo who was basically born with her chakra, shared it with the people.
But kaguya was power hungry and filled with gluttony

And "that's" when she/juubi attack wanting to get the chakra back.

I don't think it was an error when madara called the juubi a she when he introduce kaguya.

 

[ObitoGokuKakashi]

Yeah it's probably like this somehow. But still, Kishi has to explain.