Most of the Order, with exception of the teachers (Severus, McGonagall, Dumbledore, and Hagrid [who was still not back]) were gathered in Grimmauld Place when Mundungus walked in late, dropped heavily into a chair, and said "You'll never guess what I 'eard this afternoon."
"I bet we can," James said with a grin, all three Marauders looking eager for the game. "Give us a hint?"
"What did you find out?" Lily asked, before they were there all night. The Marauders looked disappointed. Lily's mouth twitched. There was a time she had thought they would never grow up, but now she was glad they could still be childish.
"Well, I was in the 'ogshead in one of my um... disguises," Dung slurred, after casting a wary eye around to make sure Aberforth wasn't there. "When a whole troop of students came in." Lily sat up straight. Dung nodded several times. "Apparently, 'arry and 'ermione convinced some of the students to participate in a defense against the dark arts group, since the ministry hag won't teach them anything."
There was a moment of silence. Molly looked horrified, Arthur and Remus thoughtful, and Sirius' eyes lit up with devious excitement.
"That can't be allowed," Lily said, finally, while James grinned. It might not be against school rules, but with Umbridge more or less in charge...
"They're going to be expelled," Molly said, faintly.
"No, they're not," said James, "First of all, they'd have to be caught, which they won't. Even if they are, Dumbledore won't let them be expelled."
"This is excellent!" said Sirius.
"No, it's not!" Molly snapped.
"Apparently, there are quite a few students willing to learn," said Remus, "That's a good sign."
"How many students were there, Mundungus?" Arthur asked.
"Ur, maybe about... twenty?" he answered.
"This means that there are people at Hogwarts who at least disapprove of what the ministry's doing, and maybe even think that Harry might have a point," Arthur said.
"It's good that they're open to learning to defend themselves properly," Tonks agreed, nodding. "When You-Know-Who does come into the open, they might need it."
"How do none of you realize that they're just children?" Molly burst out, "They don't need to know how to defend themselves; they need to get their education. This war won't last forever, and they can't just throw their futures away."
"It's better that they know how to defend themselves," Lily insisted, "There's no telling how long Hogwarts will remain safe. And what about between terms?"
"You can't honestly expect them to just take that old toad lying down?" James asked, indignantly.
"You raised us to stand up for what is right, Mum," Bill pointed out, quietly.
Molly opened and closed her mouth, as if not sure what to say to that.
Sirius started scribbling on a sheet of paper. "I'm going to talk to them tomorrow night."
"I'll talk to them too," Molly said at once.
"You're on guard duty," Arthur reminded her.
"Besides, we can't all just jump in and out of the fire to say something to them," Lily said, practically, "It would take too much time and draw too much attention."
"Well, then, tell them that my children are on no account to whatsoever to take part in illegal groups. They'll be expelled for sure, and their futures will be ruined. There will be plenty of time to learn to defend themselves later. They're too young to worry about that now. And I know that I have no authority over Hermione and Harry, but tell them I strongly advice against it, and I only have their best interests at heart."
"Well, tell Harry I think it's a brilliant idea," James said. Sirius grinned at him, and Lily nodded.
"You will tell them, Sirius, won't you?" Molly asked, anxiously.
"Yes, yes," said Sirius. "I promise," he added when Molly remained unconvinced.
"Well," said Kingsley, with a slow smile, "It seems that this meeting is over."
Molly's message to the trio is almost word for word from the book. I got the impression Sirius was quoting her rather than paraphrasing.