This is for my mom, so I can’t provide all that many details. It is a book that she read in the 60’s, so could have been published in the 1950s or 1960s. It is about two turtles who are walking to school. One detail she remembers is that they were carrying books wrapped in cord or twine instead of in a back pack.
Stump the Bookseller
New format, same book stumper solving.
Not quite a match, but you might take a look at ‘Tubby Turtle’ by Helen Wing. It’s a Rand McNally Elf Book from 1959 about a little turtle going to school. The front cover shows him walking to school, with his books tied up in a strap. I don’t know that he walks to school with another turtle, but he does have other animal classmates, including Rabbit, Squirrel, Possum, and Chipmunk.