Line Ettiquette

I'm at WalMart. I've got to return a duplicate gift (yes it's the perfect pushups-- what does that say when I got two of them?). I get there and there are two stations at the returns counter. There is one customer at each, with some family in tow. And there's one lady in front of me.

So what's the etiquette here? Is she required to pick a lane like the bank lanes in drive thru? For this situation, she doesn't have to pick. Next person is her. But she hangs back like twenty feet. So much so that when I walked up, I had to make sure she was in "line." So now the world is between us and the counters. I want her to move up.
Why? Because-- oops- there you go, someone else just walks right up to the counter and stakes a claim. If Hang Back Lady moved up some, there wouldn't be as much question. I clear my throat. Move up a little close into her air space. Finally she moves up a step. Need more like twelve. Another claim staker swoops in. They get a quick answer and fill out a form.
Finally Hang Back Lady's motioned to step on up to the counter. I move way up and the line that has now grown moves up with me. There's no more room to claim jump. All is well in WalMart Return land.