Oh, this is so funny, and so sweet. I love grown-up-but-still-pretty-clueless Harry, and reluctantly-famous Snape is hysterical. You do a really good job with Snape's dialogue, in particular, the perfect blend of funny/snarky/cutting/true.
Jessamine is adorable, and quite a character in her own right, which is an accomplishment, given her extremely limited vocabulary.
Dudley's appearance was a surprise, and a clever explanation for Jessamine's sudden appearance, and the 6 Months Later scene is awesome, from the inappropriate toys to the very last line.