I would love to help but I am not good with analysis but you should read the poem if you haven't already because it is good :-)
The simple predicate of the sentence "Most nurses work in hospitals" is 'work'
Then she tells him her plan: while Duncan sleeps, she will give his chamberlains wine to make them drunk, and then she and Macbeth can slip in and murder Duncan. They will smear the blood of Duncan on the sleeping chamberlains to cast the guilt upon them.
