Answer:
The first funny/ironic fact about the Finch family's history that we learn in Chapter 13 is that the Finch family married within their own family for many generations.
Another interesting fact that we (the readers) learn is that the Finches cousin Joshua attempted to shoot the president, and went to prison for many years.
These examples are just two of many that imply the Finch children are, perhaps, not from the finest family lineage.
Explanation: