"Mom is exactly like Angela Lansbury," explains chrisheadrick, who's looking for a place to "tickle her senses with dainty, pretty things or lovely, genteel surroundings."
Hounds jumped on the case. Some recommended the Garden Court at the Palace Hotel, which serves breakfast, lunch, brunch, and afternoon tea. "Ohmigawd," said the OP after reviewing images of the hotel's teatime layout, so it seems we have at least one winner.
The "genteel" Hayes Street Grill wins a vote from ML8000, for whom it resembles "a convent in the English countryside."
But would it suit a meddlesome mystery writer from Cabot Cove? Guess we'll find out when the reports arrive.
Garden Court at the Palace Hotel [Financial District]
2 New Montgomery Street, San Francisco
Hayes Street Grill [Hayes Valley]
320 Hayes Street, San Francisco