I never watched it before very recently.
I have been watching it on MeTV for the last year or two.
And yes, a lot of very pretty actresses.
Now why didn’t Perry ever marry Della?
He had a medical problem in his wrist.
I have never read any of the books but my guess would be that Erle Stanley Gardner wanted there to be a bit of romantic interest. Also Paul Drake always liked her.
I read a good article in Sports Afield or maybe Outdoor Life in the early 60s by Gardner. It was about survival guns and he thought everyone should have a Smith & Wesson model 17, 6 inch barrel. I agree. It might have had a different name back then but the same gun, a .22LR on a medium frame.