I found three books today at my local library and thought I'd let you know. They're aimed at people raising their children in Patagonia, but I know of a few trilingual families here in Wales who could benifit from knowing about them. They've got "Hugen Fach Goch" - Red riding Hood, Tri Mochyn Bach - Three Little Pigs, and one more, which I've forgotten 
Okay, that's all.
enjoy 