You are right in identifying the importance of the point of view in this story. As the tale is narrated from the first person perspective, coming from Scout, we see everything from the point of view of a child, and therefore the description is full of her perspective and thoughts. Your original question had to be edited for asking too many questions, so I have chosen to focus on how Scout describes her mother:
Our mother died when I was two, so I never felt her absence. She was a Graham from Montgomery; Atticus met her when he was first elected to the state legislature. He was middle-aged then, she was fifteen years his junior. Jem was the product of their first year of marriage; four years later I was born, and two years later our mother died from a sudden heart attack. They said it ran in her family. I did not miss her, but I think Jem did. He remembered her clearly, and sometimes in the middle of a game he would sigh at length, then go off and play by himself behind the car-house. When he was like that, I knew better than to bother him.
What is of interest in this account is Scout's very matter-of-fact response to her mother. As she was only two when her mother died, she hardly remembers her and "never felt her absence". Scout says that she did not miss her mother, but then goes on to show sensitivity and understanding in narrating how her brother does, and how he reacts to his grief and his feeling of her loss. Scout thus shows a realistic reaction to the mother she in a sense has never known, as well as her perceptiveness in determining that her brother, Jem, is still affected by their mother's death.