What is the main conflict in Birds, Beasts, and Relatives by Gerald Durrell?

The story opens with a prelude called "Conversations" that occurs during a reunion of Gerald Darrell, his siblings and his mother in which he announces his intention to write a sequel to his first book, "My Family and Other Animals." His mother initially tells Gerald's brothers that she can't stop the project, but when he proposes to include a particular story about his mother, she joins in the objections. Gerald notes that, considering the number and intensity of the arguments against the project, there's only one thing to do: Sit down to write.