What comment did Miss Mebbin make after Mrs Packletide had fired the shot?

Why did Miss Mebbin make this comment? How did Mrs Packletide react to this comment?

Miss Mebbin brought to everybody’s notice that Mrs.Packletide had not killed the tiger but the goat. The tiger died because of a heart-failure caused by the sound of the gun shot. Miss Mebbin intended to blackmail Mrs. Packletide with this piece of information. She wanted to take more money from her. Mrs. Packletide was very annoyed at this disclosure. However, she told herself that Miss Mebbin was only a paid companion who would keep the secret to herself if given more money.