How did Miss Mebbin manage to get her week-end cottage

How did Miss Mebbin manage to get her

week-end cottage? Why did she plant so many tiger lilies in her garden? 

Answer: Miss Mebbin managed to get her week-end cottage by blackmailing Mrs. Packletide. She had threatened Mrs. Packletide that if the latter would not buy her a cottage, she would reveal the truth toeverybody including Loona. 

She planted so many tiger lilies in her garden in order to pay a tribute to the dead tiger because of which she was able to possess the cottage. These tiger lilies would constantly remind her of her hunting expedition with Mrs. Packletide.