The Crystal Navigator

"Eleven year old Lucy Nightingale is a special little girl. She can make things with her thoughts. However, she lost her confidence when her mind went blank during an oral report. Then a dazzling new teacher assigns another report about five paintings. Convinced that the only way to get an A on this assignment is to actually talk to the artists, Lucy summons a Wise One to help her with time travel. Her Wise One shows up in the form of a loveable, well-spoken, befuddled Corgi named Wilbur. He wears spectacles and reads brochures about liquid mirrors. With Wilbur's magic gadget, the Navigator, to guide them, Lucy and Wilbur fly back to fifteenth-century Florence. The journey turns perilous when the Navigator contracts a virus and propels the two friends into the wrong time. In triumphing over the obstacles Wilbur sets in her way, Lucy finds her self-confidence and more." – quoted from this book's product page on Amazon.com as of 2018-01-23.