for It Only Looks Easy by Pamela Curtis Swallow
Before the first day of seventh grade is over, Kat Randall's year is nearly ruined. When her beloved dog, Cheddar, is run over by a woman with Alzheimer's disease, Kat reacts impulsively, leaving school on a "borrowed" bike. If "one of the best years" of her life starts out like this, what's next?
Publisher description retrieved from Google Books.