The mysteries of time and the mystery series protagonist
The Wall Street Journal looks at the fictional heroes of some of the biggest mystery franchises - the top-selling genre in 2010 - and how their authors are dealing with the problems of time. Some have stopped time altogether, others have their characters age very, very slowly, and some are coming up with convoluted excuses as to why their good guys are still out there trying to catch the bad guys, despite bad knees and the need for reading glasses.
Pretty much every author wished that their character had started the series at a younger age.
One thing I’ve always had to think about with female characters - the older they are, the less plausible it is that they can get pregnant. I had one series where the character started out at 39, and later I really, really wanted her to have a baby.