Grandma is an Alien audiobook

Six-year-old Ethan and ten-year-old Bea are confused. Grandma looks sad. She hurts all the time. She's got dark circles under her eyes. She can't even toss a ball or frisbee with us anymore. Grandma just doesn't look like herself. A shooting star for a UFO convinces Ethan and Bea that Grandma has been possessed by an alien. Adults call it arthritis, so people won't be scared because it's catching. Ethan and Bea fear the alien take over Mom, too.