Hey there =) I'm Laurie and I have a couple characters here.
Bill Weasley - obviously knows Percy. Thinks he's a ass for abandoning his family like that. But times do change and well, there's always a chance to make amends. Right now, he's so wrapped around the fact that the DE's have Fleur that he's taking it out on everyone. (Sorry Ginny!) Drinking, cursing, and violent behavior are on the agenda for now. (What can I say? He blames himself. He'll calm down once she's safe.) Anyway... He's the one that would know Percy.
Lavender Brown - Fashionista in training... hopes to one day take the wizarding fashion world by storm. She's not opposed to striking up a random conversation through journals so you might hear from her every once in awhile.
Astoria Greengrass - Spoiled, expects the world to listen as she rambles on about radomness. She loves to cook/bake/all of it, and likes to show her food off. She doesn't know much about the Weasleys except they're poor and breed like rabbits. Chances are she won't have much to say to him at all. Unless he ends up writing something she might find interesting.