I can't tell if i'm thinking right or am putting to much thought into this BUT!
Minnie's spirit form that was "placed" into Finklestein's creation is what I think was her soul.
The only organic part that I believe that was implanted into the "creation" was Mimi's original left eye, which still has significance with her being part Nergal and that the left is also symbolic in the fact that it is also used as a nergal ritualistic sign in "romance(i think would be the best word)". It is apparent that she still has power her original nergal symbiot to which allows her to command it as shown in their scuffle with mimi outside of the vault(then again it just might be the fact that Minnie's pre-existing knowledge of nergal tongue allowed her to communicate with symbiot in that situation to which it "willingly acted on her wishes(tentacle snare)).
If i'm correct, Sally was created from scratch as a ragdoll that possessed no organic parts(technically), Minnie's new body(Finklestein's creation) bears a striking and very much so apparent resemblance to Sally's design to which did not require any biological or organic maintenance( as far as i can tell ) in her functionality. All that was required was science to which Finklestein's S creation (sally) i think naturally manifested a personality ( soul i guess in this case... idk) to which it began to act upon. Finklestein's new creation (the minnie body) would've possibly bred it's own naturally formed soul manifestation in time. HOWEVER! A pre-existing soul was implanted into the "creation"(Minnies Soul) before the gift of life was instilled into the creation thus preventing a soul manifestation in lou of a soul transplant(Minnie's).
The left eye of minnie's i believe does NOT require organic support but spiritual, this is due to the transplant into Junior to whom does not have a organic system but the eye managed to sync to what i believe was his soul to which it became one with him( just my thoughts). Thus the nergal symbiot biology replicated amongst Juniors body( the eye is the source of course( heh... that rhymed( kind of...))).
Thusly, the apparent transplant of minnie's original eye was a simple task to which when Minnie's soul was transplanted, her left eye (i guess is still part of the nergal symbiot) attached itself to her soul.
In conclusion( I guess, hopefully... I'll probably be back to edit this since it was nothing but a ramble...)
Minnie's new body = all ragdoll *with the exception of the left (nergal symbiot piece) eye.
Minnie's soul is present in said body; transplant of soul (i guess) would be difficult unless the original guardian( can't recollect his actual name) still dubs that it is not her time ( or she can't go to heaven yet... whatever, their in the underworld i guess anyways...) to which then they COULD transplant Minnie's soul in the future to a more age appropriate body design ( i'm just going to assume that her soul manifestation form will mature naturally) with mere means of the left eye being re-transplanted into the new body and that body being gifted with life( now that i think about it, it might not be the gifting of life but fusion/creation of body and soul... her soul already existing and what not... Ahhh!!!! i feel so redundant!!!
You know what... fuck it. I'm ending this post now. I have things to do. College things. Good day...