It is a rather old-fashioned term but I think it has rather quaint connotations. I can just imagine two elderly ladies talking on a park bench about a third old lady:
Winnie: Have you seen Brenda recently?
Glenys: No.
Winnie: I think she has a little secret.
Glenys: Oooh, really? Go on, tell me.
Winnie: Well, last week, I was peeking through my net curtains and I saw a man going up Brenda's front path.
Glenys: No! She had a gentleman caller?
Winnie: Yes. And not for the first time this year either.
Glenys: Oooooooooooooh! Lucky old girl. Ha ha!
(Most of that would be said in the manner of Les Dawson and Roy Barraclough in the two old women sketches. If you have no idea what I'm talking about, watch
this.)