Yes, they are brother and sister

She writes murder mysteries not romance. A lot of the police do try to get her to stay out of their investigation she just doesn't listen.

1. She is not "an old lady." She represents mature professional women. During the 1980's women were beginning to become accepted in most work places and then followed older women as age discrimination was a problem. Shows like this one and The Golden Girls became very popular with even young people.

2. She began solving crimes in her hometown and because she is a bestselling mystery writer, she won world acclaim and respect for both her books, her research and of course the solving of many crimes. A lot of police detectives are fans of hers and ask for her help.

3. There are just as many detectives who resist her, seeing her as a busy body. However, by the end of the show she has won them over with her wit and logic.

4. Rarely does she intrude on an investigation, even when some detectives are one egg short of a dozen. She kindly urges them along by giving them credit for all the steps taken to the final solve of a crime.

According to two episodes in Season 12, Jessica Fletcher wrote at least 23-26 books. In S12, E11: "Unwilling Witness" Jessica is subpoenaed to testify in a grand jury and is asked how many books she has written, to which she responds that she'd just finished her 23rd book. And, in S12, E22: "Southern Double-Cross", one of the other characters is reading the author's biography of her latest book and they note she's written 26. Both episodes aired in the 12th (and final) season, so it's a safe bet that Jessica had the potential to write more, as she was not presented as being close to retirement.

In at least one episode, Jessica Fltcher said she didn't drive.