My goodness, this is glorious. Absolutely glorious. Wonderful, mature characterisation, complex and believably extrapolated from their younger selves, with a few fun surprises (Draco as a Healer ... yes, indeed!)
I'm completely sold on this pairing the way you tell it, with Millicent being everything to Harry that his wife is not (and I really like your Ginny, too!), and I love her curves and heavy breasts and pale skin. Her choices make full sense for her, the sex scenes were fantastic, and the progression, with the sensible, scandalous, mature resolution is the perfect note on which to end this.