^Didn't they meet when
one of Foaly's new cameras accidentally recognised her as a criminal and he ended up having to make a personal apology? 
Because Colfer doesn't do much worldbuilding until he really needs to (and also because I'm not good at noticing these things), I do find Caballine's ~**Magic Sparkle Faerie Skills**~ plausible... Like it does fit into the world he's made okay, and it's not the first time we've randomly been introduced to new stuff (to make a plot point, which is admittedly slightly lazy writing...)
To be honest, I'm slightly annoyed that the Good Ship HT was sunk

It was my only non-canon surviving ship in the Fowl series!
