Mired has several meanings but in this case it refers to being entangled.
The scenario above tells of a situation where an Act to provide for better healthcare to Veterans, the VA Mission Act, had not been passed due to budgetary issues.
In using the word ''mired'', the author wanted to describe that the Act had not been passed because it had been entangled in budgetary disputes between different parties.
When Scout met Dill she said she was "Goin on seven" and that Jem was "4 years my senior" meaning that Jem was 10 & Scout was 6. Yes it is important to keep Scout's age in mind throughout the novel, because you can be more open-minded to how she is and the way she acts.
