They seriously named a character "Oh lala"?

I was curious who the actress was that played Roberts sister, so I came here. I figured she was called Alala or something since that's pretty much how he pronounces it, but now I see they actually named her Ollala.

Now I'm wondering if it was some kind of in-joke or just lack of imagination. "Idk what to call this character, let's see what we got to work with... ok, she's young, she's blonde and she's hot. let's call her "oh'lala""

Oh well, maybe it's a common name somewhere and I just don't get it. :p