Considering that the demons are god kin, we're actually not sure now how they came to be and what Eve had to do with it. You're thinking of the original explanation that we went with. Eve's not "a demon of everything", nor is she actually the Sloth demon--she is in the place of the Sloth demon, and everyone assumed she was, but she is not a demon, she's a spirit.
The Clockworker's Doll is the same vessel as it has always been, yes, but it didn't have a mind of its own. It had Eve's soul inside it. It didn't "use" Margarita to become the Sloth sinner--Eve thought she was Margarita. The Sloth demon doesn't exist, and the "Sin" of Sloth doesn't mean anything at all. It's not a tangible thing. There are no "Deadly Sinners" in universe--they're known as contractors, and there's nothing special about their contracts, they just happen the important contractors that are highlighted for narrative purposes.
Michaela is not related to the doll whatsoever. Are you talking about Michelle?