Ummm... I'm not so sure they do. I just read through the whole lava-incident section, and all I could see was Nudge referring to the baths she was forced to take, Tsillah calling Nudge "sis", and Monica referring to this relationship later.zachariah wrote:She did. She is the younger sister of Nudge and was around while Nudge was still being given baths by her mother. THe comments between them after Monica threw Nudge in the lava clearly show They did grow up together, or I think they show that. lol.AnotherFairportfan wrote:the age of a certain doofus - unless she was lying to Shelly and Justin, she IS younger than the others...
Tsillah pretty clearly knew Nudge couldn't be harmed by lava (she wasn't concerned for Nudge's safety), hence she probably knew about Nudge's childhood baths, but I don't see anything which says she was actually there (or even alive) when the baths happened.
Have I missed some relevant dialog?
Phix originally referred to Nudge in a way which suggests she's quite old ("one of the original tricksters" IIRC), and Euryale confirmed this (Nudge is older than she is, and Euryale is at least a couple of thousand years old).
Tsillah on the other hand was still in school when Shelly and Justin first met her. Tsillah could be very old and perpetually immature (some form of demigod development disability, perhaps) but this doesn't really jibe well with her apparently being in school in the manner of a normal teen.