Sentence structure

Hi!

I am not sure which are the constituents and their functions in the following sentence:

She will be wearing a white dress with a dropped waistline.

NP(she) function- subject; VP (will be wearing) predicate; NP (a white dress)- DO or complement of the verb? PP(with a dropped waistline) OR NP (a white dress with a dropped waistline)- DO or Advl Complement.

Could you please help me?