Well, she could float next to him, but he would probably keep sneezing! Molotov, frankly, thought she was being considerate, and Spike should be grateful for it.

She looks quizzically at him when he stops, but then he says that and she bares her teeth, launching herself at... his ear. It's about all she can reach, so she pulls and slaps at him, screaming little chimes of fury at him. Is she angrier than usual? It's possible. Such a tiny body probably can't handle too many emotions at once.