"You'll be fine," she assured him. "And we'll all be behind you." She paused. "Not literally, because I doubt you want us shadowing you all day ..." she grinned a little.
Though honestly, she couldn't see it being allowed, ultimately. Surely this was just a bit on Narcissa's part to fluff up the Malfoy credentials ... and they wouldn't let Astoria run the school.
But if they did, and if she turned out to be anything like Umbridge ...
"Maybe I should do a section on Muggle pranks this year," she mused. "Things Muggle kids use to amuse themselves." And maybe she'd go through a list of what Muggle kids did to substitute teachers and see if those planted seeds grew into ideas.
If she had to, of course. A little smirk played over her lips before she lifted her head and patted Neville's shoulder, squeezing gently.
Maybe in time the Ministry would learn it wasn't welcome within the walls of Hogwarts - though she doubted it.