Just finished all four books of the Legends of Korra a week ago and I wonder if by the end of book 4 if she can really be called a fully realized avatar despite the fact some characters call her one and how the end of book 1 does solidify/confirm it.
Despite the fact she does master all four elements even earlier than some previous avatars (Roku for example) she doesn't show the same ingenuity or even raw power output with the four elements without constantly using the avatar state which is odd. I suppose that's why they kept taking away her powers and such in later books but it still leaves a bad impression of Korra despite of how good a character she is.
Is the fault of her water/earth/fire masters from the white lotus being somehow not as open as previous master benders that taught the other avatars?
[I wouldn't include Toph as her master obviously because she was only helping Korra get over some of her trauma as well as the poison.]