Why is Thisbe worried when Madame sends her to Byron's room to take his letters?

Thisbe is worried when Madame sends her to Byron's room to take his letters. She remembers a former housemaid named Josephine who had opened a drawer. Because she had nothing to put in it, she was convicted of stealing and sentenced to a slap from Madame, five lashes from Lucien, and a sale to a hardworking farm. She worries that she will be accused of stealing and punished in the same way.