It fits her well, she just likes to get you with games at unexpected times. She's totally vain, I love her! I can definitely see her chatting him up at some point :D It'll be hilarious!
Because she is AWESOME and much prettier than Pansy. Obviously. Depending how close they were as friends (assuming you CAN) she may have written to him at Azkaban. I assume you can but...yeah, who knows, JK is crazy.