Molotov's response is much the same as it is when she's woken as a regular size human -- she murmurs(/chimes) a grumble, then shifts a little. Her wings also twitch a bit, but that probably just goes along with the getting resettled in his hair.

Which, yes, is covered in fairy dust. He'll have to pretend he was hanging out with strippers or something.

But there's nothing in his hair besides a fairy now, since her hat has fallen to the ground. And she would really appreciate it if Spike picked that up for her.