Tom Percival 
Darllen yn Well: Pryder Glain [PDF ebook] 

Ruby loves being Ruby. Until, one day, she finds a worry. At first it”s not such a big worry, and that”s all right, but then it starts to grow. It gets bigger and bigger every day and it makes Ruby sad. How can Ruby get rid of it and feel like herself again? A perceptive and poignant story that is a must-have for all children”s bookshelves. Welsh adaptation of ”Ruby”s Worry”.