Lucia Corina is definitely noticing the way John's shape shifts in slight and less-slight ways, but she's not doing anything other than noticing. She is curious what he is, but it's very rude to go around asking people what they are! And he's a very polite whatever he is.

"Any light, or if it's just the lightning, and if it's any noise, or just the thunder? Hm. Noise, I can produce, but I can't make light without fire, and this is not an environment inviting to flame. You heard me singing, right? Could you still hear anything else, once you started hearing me?"