For the first example, I have a question. How do we assume that Sara has only one brother? If she has one brother, why is it needed to give his name? I mean, it would be enough to say only "her brother" if she has only one? Am I thinking in the wrong way?
No it's like ..if Sara has more than one brother then the text must be in the way that,Sara's younger or elder brother....it is not mentioned so that's why we assume it as Sara has only one brother..
