Daisy's Aunt by E.F. Benson

Daisy's father and mother had both died when she was quite young, and not yet half-way through the momentous teens. For seven years after that she had lived with her mother's sister, the inimitable Aunt Jeannie, whom she wished to see every day. But though she had passed seven years with her, she had barely seen her aunt's husband. It was his death, a year ago, that had sent her to the Nottinghams, for Aunt Jeannie in a crisis of nerves had been ordered abroad for a year, and was now on the point of return, and, having returned, was to stay with Lady Nottingham for the indefinite period which may be taken up by the finding of a suitable house.

Daisy knew there had been trouble at the back of all this. Uncle Francis, Aunt Jeannie's husband, had been called an invalid, and she gathered that his ill-health was something not to be openly alluded to. Morphia was connected with it, a "habit" was connected with it, and since this was somehow disagreeable, she had long ago so successfully banished it from her thoughts that her curiosity about it was a thing without existence. Certainly he made Aunt Jeannie very unhappy, but Aunt Jeannie, who was such a dear, and so young still -- not more than thirty, for she was the youngest of a family of whom Daisy's mother was the eldest -- had been always sedulous to hide disquietude from her niece. And it was entirely characteristic of Daisy to be grateful for having it all hid from her, and not even in thought to conjecture what it was all about.