The boy is ignorance and the girl is want, in my opinion (you may have a different take on this) they symbolize the poor. Throughout the novella, we have seen the good side of the poor through the Cratchints who work hard day in day out, and now Dickens is wanting to show how malnourished the poor really is. It can also show how Dickens is saying that if the government doesn't act and help out the poor as well as everyone else, this is what the future for the poor will look like, malnourished and uneducated. It is showing us the consequences of being basically abandoned from society in general, abandoned by the education system, and again, I think that Dickens here is trying to show the consequences of the abandonment of the poor and how the government and the rich should change their ways to stop that from happening by being kind and charitable ect.
