What Jostein Gaarder means in here?

Hello philosophers!

I was reading a Chinese version of Sophie's World and found some inappropriate translation. I would just want to confirm what I thought the original meaning was in the following paragraph excerpted from the beginning of the chapter "Socrates":

'You've become very interested in the newspaper,' said her mother drily when Sophie returned to the kitchen.

--------p.49 Sophie's World, Phoenix Press, paperback

I thought the word drily means in a sarcastic sense rather than the way describing the voice as translated in the Chinese version. If any one of you could remember this part tell me I'm right! :wink:

[Tdol]

It's sarcasm.