The Tree of Knowledge of Good and Evil
On the surface it would seem that Eve must be referring to the tree of knowledge of good and evil when she told the serpent that they weren't to eat from the tree in the midst of the garden. We know that the Lord God told Adam not to eat of the tree of knowledge of good and evil.
The story should be accurate as written. If it makes good sense as written, then we shouldn't try to fix it through reasoning. The story clearly says that the Tree of Life was in the midst of the garden.
Go back and see if you can agree that the Tree of Life would be the one in the midst of the garden.