In the book Walk Two Moons by Sharon Creech ,chapters 1-11, what reason do Gramps and Sal’s father give Sal…

In the book Walk Two Moons by Sharon Creech ,chapters 1-11, what reason do Gramps and Sal’s father give Sal for going on the trip?Accourding to Sal, what are the real reasons? Why might the reason have been left unspoken?