How do you narrate a story?

Colonel Sartoris

6ish, Because she is going into Primary school

The story is a double and triple frame. The main narrator is the Captain of the ship caught in the ice of the Arctic Ocean. The secondary narrator is Dr. Frankenstein himself recounting his life....

I believe it is 2nd person narrative quite rare

You can use any narrative viewpoint you want to use -- most authors use third person because first and third are quite tricky to write properly.