6. I found a picture of an Egyptian goddess in a history book. In the book it is stated that she is one of the four goddesses protecting the canopic jars of Tutankhamun but it was not said which one. The picture I found does not show what she has on her head. I should guess that she is Nephthys but I am not sure.

Yes, your picture shows the goddess Nephthys and she can be identified by the slightly damaged part of her right eyebrow and the somewhat unusual shape of her right ear. The statuettes of the four goddesses Isis, Nephthys, Selket and Neith were placed round the shrine which contained a canopic chest with four cavities (there were no canopic jars as such). A miniature coffin containing Tutankhamun's internal organs was put in each of these cavities. These are the pictures of the statuette of Nephthys and the shrine taken by Harry Burton: