Im guessing by 'do' you mean her profession. Well for some time she was a nurse, but she is famous for being a crime and detective writer.
She had one girl name Rosalind
There are several websites dedicated to Agatha Christie and her works. An author's website doesn't exist, as Christie died in 1976.
Her sister Madge who sold some short stories to a magazine. Then her mother who recommended her to write something when she was bored during having a flu (or some illness like that).
Yes. A terrier named Peter.