She doesn't laugh as much as she does smile in response, her eyebrows raised at the joke but her mind sliding over it easily enough. Instead, she squeezes her hand and breathes out, swallowing a little as she moves to adjust his arm, his posture, ever so slightly, into something more familiar - her days as a member of the DA might be in the past now but she recalls all the lessons from Harry, still uses them now.

"It's not something that anyone gets the first time around. It's very advanced magic and it took me ages to get it right and I still sometimes struggle. A lot of it has to do with the power of your memories, your thoughts, and your self-confidence... Not that I think you have much to worry about in that regard."

Her smile is a little more teasing, now, her elbow nudging his side before she breathes out and closes her eyes. Her own movements are by-the-book perfect, as always, but something a little like fear prickles over her face when she tries to focus on her own happiness, the sum of it blotted out by the last few months. Rather than allowing herself to dwell on joy she gets caught up in thinking too hard (not for the first time) and when she casts the silver of the spell itself just seems to come out as a useless fog.

"Oh."

Swallowing, Hermione glances at her wand, her cheeks burning a little before she lifts her head and breathes out, determined not to let on just how much this failure was prickling at her.

"Like I said, even I struggled with it."