1) The passage discusses the experiences of being an only child from the perspective of journalist Sarah Lee. She found it difficult to make friends when she went to boarding school at age seven, as she was used to spending time mostly with adults as an only child.
2) Being an only child gave her insight into the adult world that children from large families may not receive. It also made her more comfortable doing things independently or with just one other person rather than in groups.
3) She now feels very responsible for her divorced parents' happiness, as she is the closest family they have. She is aware of her important role in their lives.