How is Nicolás' mother portrayed in the short-story collection, Lot?

Nicolás' mother is depicted throughout the collection as a lonely woman, who feels increasingly abandoned by her family, as first her husband leaves her, then her daughter gets married, then Javi dies, leaving only Nicolás behind. Nicolás recalls his mother being friendless in the neighborhood because she was a Black woman married to a Hispanic man, and consequently did not fit neatly in with any racial group.