In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

He was the son of actor Peter Lawford and Patricia Kennedy Lawford .
He was a member of the prominent Kennedy family , and son of actor Peter Lawford and Patricia " Pat " Kennedy Lawford , who was the sister of President John F. Kennedy .

A head teacher ( also called a school principal , or headmaster / headmistress ) is the teacher in charge of a school .
A head teacher , headmaster , headmistress , head , chancellor , principal or school director ( sometimes another title is used ) is the staff member of a school with the greatest responsibility for the management of the school .

The Amborellaceae are a line of flowering plants that diverged very early on ( about 130 million years ago ) from all the other living species of flowering plants .

That is , the Amborellaceae represent a line of flowering plants that diverged very early on ( about 130 million years ago ) from all the other extant species of flowering plants , and , among extant flowering plants , is the sister group to the other flowering plants .