I had never heard of a charwoman before. Although I hated Dickens, so I avoided all books by him like the plague.
Btw, Binks...
You can bring up your info about the plague while talking about some of the paintings from that time period. We learned a quite a bit about it in my art history classes.
Take, for instance, this painting by Antoine Jean Gros, "Bonaparte Visiting the Pest House in Jaffa". Napoleon is depicted touching victims of the plague. The plague was easily spread to others, so this would be seen as a very brave act. Napoleon's campaign wasn't going very well, so this painting was done as a piece of propaganda to show that if he could "conquer", so to speak, the plague, then he could conquer and win the war as well.