As for how Jem and Scout are specifically treated, it would be fair to assert that the townspeople show them some grudging respect. They are upset by Atticus' decision, and yet they fail to challenge the children directly. Their respect for the Finch family leads them to show respect for the children. Scout overhears the word "rape", but besides this, there is no direct contact from the town. They do not approach the children in an attempt to dissaude Atticus - that would not be considered proper for such an established family.
What we see in Chapter 14 is the tension in the Finch household since Atticus agreed to defend Tom Robinson. Atticus knows how the people of Maycomb feel about him defending Tom, but he refuses to let their opinions deter him from doing what he knows is right. Atticus and Aunt Alexandra are arguing over how he raises Jem and Scout, and Jem threatens to spank Scout if she causes any more problems that will make Atticus worry more. This tension is setting up the events that will occur as a result of Tom's trial, including how the citizens of Maycomb treat Atticus, Jem, and Scout.
Jem and Scout aren't treated very well in Maycomb. Due to the fact that their father, Atticus is deffending a 'black' man, normally in Maycomb that would be a bad thing. So during this situation, they are disrespected and very unapreciated.