To kill a mockingbird chapter 10 and 11

I feel sort of bad for Jem and scout because their dad can't play football with them. I wonder how old he is. It is probably most likely because he doesn't have enough time, because even a 60 year old can throw a football. The title of the book first appears in chapter 10 when Atticus refuses to teach them to shoot and says killing a mock bird is a sin. I don't really understand what is so special about a mockingbird, maybe it is just used a symbol. I found it strange how everyone had to be notified when the dog was spotted because it probably had a disease. Jem takes his birthday money with scout and go down the street where they pass an old lady who yells at them. Probably because she is old. Also because her dad likes African Americans. They get back at her by smashing her flowers. Their dad punishes  him by reading to her everyday. And at the end we find out it is because she was dying from withdrawal and the reading helped. Oooomg