Familiar though Hermione may be with Spider-Man, her first reaction to something being vastly out of the ordinary is to worry and assess. Spider powers don't come out of nowhere, she thinks; in fiction, she's fairly certain that the abilities were passed on by an actual spider, and in Darrow, Hermione is inclined to believe that there's been some trigger as well. She rushes to Stiles' side, her expression almost comically contrasting with his. Replace excitement with worry.

He's a good friend, and Hermione doesn't want to risk him being hurt.

"I don't understand. Did you do anything that might have caused this? Or were you bitten by some type of creature?" Hermione asked, carefully reaching out for Stiles' wrist and examining his fingers at closer length. She pulls out her wand, waving it in a circle through the air until she's conjured up a large magnifying glass that she allows to float in the air, staring at the pads of Stiles' fingers. "Don't misunderstand, I'm happy to learn that you have new powers if that's what makes you happiest, but I don't want to trust this too much before we've learned of its source."