what progress does sissy make in the gradgrinds family?

The characterization of Cecilia Jupe as a student who is trying to make "progress" in her relations with the Gradgrinds relies upon an allusion to the epic, Pilgrim's Progress by John Bunyan. As this work is about a very devout character (named Christian) who tries to get to Heaven (called the Celestial City) and avoid sin (in such places as the Slough of Despond), you could say that Dickens' use of this "Progress" is intended as irony. The reference to Bunyan's work might not be obvious but once it is pointed out, the reader should consider the different types of "progress" that might exist. Dickens lived during the great "Industrial Revolution" of Great Britain and the Gradgrinds are certainly part of this revolution. Still, Dickens suggests that this economic and scientific progress should be matched with moral and artistic progress.