Read the passage from "the tell-tale heart." i think it was his eye! yes, it was this! he had the eye of a vulture–a pale blue e
ye, with a film over it. whenever it fell upon me, my blood ran cold; and so by degrees–very gradually–i made up my mind to take the life of the old man, and thus rid myself of the eye forever. which unspoken question creates suspense? who was the old man? how did he kill the old man? where did the old man live? why did he kill the old man?
An independent clause is a sentence or part of one that can stand alone.
So I have a feeling that the first one is correct as "My sister and I love to cook" and "we spend hours cooking together" can both stand alone yet are joined by a semicolon.
