When I first read the poem I was a bit lost and confused.
I asked myself what the 'deer' represented and reading your post, I agree with you that the deer was a metaphor for a young maiden who was possibly raped, "do not touch my apron, sir and don't set the cur to barking."
There is almost a sense of surreal beauty of this heinous crime.
A young girl frozen in time.
It also appears that she has been there for awhile in the woods, "a madien white as marble."
It is definately a sad poem of a young girl who was taken an advantage of possibly by her master.
I also agree that this possibly served as a warning to other young maidens to not be swayed by strange men to be firm and vocal.
lc