Lena wouldn't have kept her conversation with "Whenny" a secret, so anyone can ask her about it. They might've overheard the spiders commenting on it or maybe even saw it themselves. Characters are welcome to ask her questions (in b4 lena why) or even use whatever rapport she establishes with Whenny to their advantage maybe.

Being compassionate is a hazard. ¯\_(ツ)_/¯