To my knowledge, the first time Trinket shows up is in... Kings of the Broken Wheel, I think, Ekuar is with the Trolls and Rayek has to rescue him and Picknose and his family... so I would guess that she was born sometime after Picknose became King but shortly before he then LOST that kingship. Gotta give it to Oddbit... she wasn't gonna settle for anything less than a King, but she didn't then LEAVE him when he lost the throne. So at the time that Rayek destroyed the Go-Back settlement she was probably very young, depending on cooking time and maturation rates. Time gap for availability is... 18 months to 2 years to Windkin's birth, then maybe 3 months or so to the Blue Mountain stuff... maybe six months afterwards for Kings 'cause Windkin is still a baby... And Oddbit wouldn't have conceived Trinket until after Picknose became king. So she'd be... maybe 2 years old depending on maturation rate and gestation?