poppy essentially spent her childhood in knockturn alley thanks to being raised by her sketchy aunt, and on a similar note makes most of her money working for dark witches and wizards, including buying and selling non-tradeable materials. i'd love to figure out some kind of connection! if he's the type to keep some questionably legal ingredients on hand, maybe she's his supplier? (they also have baking in common, and she may challenge him to a cupcake showdown)