"Anyone's only ever as good as their partner," she points out with a genuine smile, and the next dance is just as much fun as the previous one. By the time they're done, she's feeling a bit thirsty, and nods towards the bar.
"Let me buy you a drink. To thank you for that." She doesn't mean anything more by the offer than buying him a drink, and she has no more qualms offering to buy a man a drink than she does wearing suits. It is who she is.