in what ways does the author introduce the murrays as a very natural family? List the ways.

I'm not sure what you mean by "natural". Meg certainly wishes she could be more like her younger twin brothers, who are both described as B students, athletic, and clearly part of the crowd at school that easily fits in.

The contrast between Meg's feelings of inferiority and her brothers' successful ability to conform will ultimately pose a key theme of the novel. According to L'Engle, conformity inevitably destroys the fabric of a society - and thus Meg comes to stand as a last remnant of individualism, initially weakened but ultimately emboldened.