[With thanks to Delphi for the modly reminder that I hadn't posted my actual comment yet. (If my head weren't solidly screwed on, I'd probably lose it . . . .)]
There's so much to love about this fic that I hardly know where to start.
Your use of language and details makes the scenes come vividly alive. A few of my favourites include a thin wooden dowel that might – if seen from a great distance by a myopic, elderly bus driver – be mistaken for a wand, the 'discussion' between Millicent and Dudley about his parents with the fear and how it brings the thoughts of violence to both of them, Dudley's gentleness with the flowers, and Petunia's comparison of Millicent to Aunt Marge ("Very...solid woman." Before Millicent can draw unpleasant inferences, Mrs. Dursley continues. "No nonsense. Knows what she thinks and what she wants and never apologizes for it. She'd have told Albus Dumbledore to leave her family alone.").
One of the firm pieces of my headcanon is that Millicent and Vince had loved each other in their time at Hogwarts, so I was thrilled to see the pieces of that relationship that Millicent was able to face in the narrative. (And, Or considering the way he looked at her and always saw her, not an easy mark, or waste of space, or the countless other dismissals she has seen in too many men's eyes. [Sigh.] Yet even this level of perception wasn't able to save him from the chain of events and choices that led him to his death--how heartbreaking.) Dudley's reaction to the bits she shared was just so right (as was Mrs. Dursley's sudden understanding and relenting in that particular line of questioning), and I had to smile at his very Dudley solution of food to the revelation that Harry is his cousin.
One of the things I appreciate most about this fic is that even the characters who cause pain and set up obstructions to Millicent and Dudley's relationship--Petunia, Millicent's dad, Vince--love. Vince loved Millicent but fell prey to the warped ideology he was raised with. Both Petunia and Millicent's dad have prejudices that cloud their vision (and at least in Petunia's case, there's definitely some justification for her fears), but they want what they believe is best for their children. Both also have enough humility to open the window of possibility a crack to at least see that their child's beloved has some redeeming qualities. It's enough to make the ending wonderfully hope-filled. Life isn't going to be easy, but there is the promise of an eventual hard-fought understanding and, of course, love.