for Bobbo Goes to School by Shirley Hughes
"It starts out as a regular trip to the store with Mom, but then Lily does a dreadful thing: she flings her beloved stuffed toy, Bobbo, high in the air, only to have him land on top of a school bus just as it's pulling away! Lily is inconsolable. What if she never sees Bobbo again? Little does she know (though the reader can see) that Bobbo is having an exciting adventure at school--and will be well cared for until he finds his way back to Lily."--Publisher's website.
Publisher description retrieved from Google Books.