Ruby has a goat for a pet, an annoying older sister, and a dad who likes to invent things. Things that always go wrong... Ruby P. Baxter's Worst Day Ever is at Oxford Reading Level 16. It is for readers aged 11 to 13 years old who are working below expected standard in their reading. The Readerful Rise series ensures that older struggling readers have books with age-appropriate content and topics, that looks like the books their peers are enjoying, but are a written at a level they can read successfully.