Who is Ralph's Mother from Shaking the Nickel Bush and what is their importance?

Ralph's mother is a widow. She has several children that she is raising alone, and Ralph is her oldest child. When Ralph travels west for his health, he leaves his mother with only a younger brother to pay the bills. As a result, he sends his mother long letters filled with lies about a new job..... thinking he is protacting her from the fact that he can't find one.