I sense a Millicent/Susan Boyle crossover! Just turn Susan Boyle over to the fanficcers; we'll see about "never been kissed." :)
Your Millicent comes across as real and believable; I like her pragmatic attitude and the fact that though a Slytherin, she's not a Voldemort supporter. I always love when Snape lives, and Dudley is a nice touch, too.