When excitement over show-and-tell causes Fiona to miss a bathroom break, Felix reassures his embarrassed friend.

Fiona has no time today — not even to go to the bathroom. She is in a big hurry to show off the volcano she and Felix made for show-and-tell. Just as the volcano erupts . . . oops! If only she had stopped to use the bathroom when she needed to! Fiona believes that everyone will laugh about her accident for the next fifty years. But with the help of Felix, her teacher Miss B., and a classmate’s trick goldfish, Fiona learns that little accidents are quickly forgotten. With the steady and gentle hand that brought Max and Ruby to life, Wells imbues these guinea pigs with the complex human emotion of embarrassment and provides the kind and gentle response that brings relief. Children will hear the message that accidents will soon be forgotten. Compassion is also shown with the depiction of both boy and girl (guinea pig) symbols on the gender-neutral bathroom's door. In multiple ways, this is a refreshing representation of a nearly universal experience.
—Kirkus Reviews (starred review)

This title offers an important and easily accessible message...Young readers will connect with Fiona’s situation and appreciate the reminder of not delaying a trip to the bathroom. A purposeful addition.
—School Library Journal