The Cats We Meet Along the Way by Nadia Mikail

Seventeen-year-old Aisha hasn't seen her sister June for two years. And now that a calamity is about to end the world in nine months' time, she and her mother decide that it's time to track her down and mend the hurts of the past. Along with Aisha's boyfriend, Walter and his parents (and Fleabag the stray cat), the group take a roadtrip through Malaysia in a wildly decorated campervan - to put the past to rest, to come to terms with the present, and to hope for the future.