In The Markenmore Mystery (1922) by J. S. Fletcher, Mr. Fransemmery, a juryman, went to Mrs. Braxfield, a rural witness, while Mr. Blick, a detective, was in her house:
Mrs. Braxfield herself opened the door of Woodland Cottage to Mr. Fransemmery, and making out his identity by the light of the lamp in her hall, bade him enter in tones of warm welcome.
“Never rains but it pours!” she exclaimed, as she ushered the visitor towards her parlour. “I’ve got one caller already, and now here’s another; glad to see you, Mr. Fransemmery!”
Mr. Fransemmery stepped into a well-lighted, cosy sitting-room, and found himself staring at Blick. Blick smiled and nodded; he recognized the newcomer as the bland and spectacled gentleman who had acted as foreman of the jury at the recent inquest. Mr. Fransemmery, of course, knew who Blick was. He hesitated on the threshold.
“If you’re talking business matters—” he suggested.
“Not at all!” exclaimed Mrs. Braxfield. “This young gentleman—too young, I tell him, to have such a job as he has!—simply came to ask me what he calls a pertinent question about my evidence the other morning. I’m a very good-tempered woman, as you well know, Mr. Fransemmery, or I might have given his question another name, and called it impertinent! What do you think he wanted to know, Mr. Fransemmery? If I was certain that the man I saw on the hill-side the morning of the murder was Mr. John Harborough? The idea!”
Blick, who looked very much at home in an easy chair, gave Mrs. Braxfield a whimsical glance.
“Well, you haven’t told me yet if you were certain!” he said.
Actually, I have three questions here:
I found that "Never rains but it pours" refers to happening of bad things, if so, how could she welcome him warmly while she regard this visit as a bad thing?
Mr. Blick was a detective, and Mrs. Braxfield was just a rural witness, so it's impossible that they were talking about "commercial business matters", so is "business" here just an adjective like "important"?
I found the possible meanings of "whimsical", but I just can't get its exact meaning in this context, so can somebody explain it simpler terms in connection with the context?