On the recommendation of the hounds (it was Burger Boy actually) we went to 26 Beach in Venice for the birthday cheeseburger. It was a unqualified success!
We had never heard of this restaurant before but what we found was a small, comfortable neighborhoody place where we slid into a roomy booth in the bar area. Service was friendly and attentive - and the food gets high marks.
The birthday girl was quite pleased (and she's picky) with her cheeseburger: a large medium rare patty with shredded lettuce and cheddar on a homemade bun. I snagged a bite and it's the real deal. My wife had a seafood jambalaya which was thick and tasty and would have fed us all if we'd ordered nothing else. Mine was the organic teriyaki glaze salmon (also a rec. from BB) which was fantastic - perfectly cooked and subtly glazed.
Constant drink refills, a complimentary birthday dessert - this was a perfect choice for a low-key occasion. Even teenage big sister was impressed and says she wants to come back.
Thanks to Burger Boy and all the hounds who offered suggestions on short notice. This is why I love this site!