
Not exactly the same but my Logan walks/runs oddly - he walks with his hocks nearly touching (he also picks them up high and tucks them in a bit) and when he runs, his whole body sort of rolls through a spiral. His body actually is a sort of spiral, which is what causes it - his right hip is dropped and moving up he then rotates over to his left shoulder, which is also dropped. So his run follows that.
He is in pain though, and is seeing the chiropractor in a couple of weeks - so no idea if it's a similar sort of thing. Has your girl maybe knocked herself or something lately, maybe tweaked her back somehow?
Remember dogs are fantastically stoical about pain - one of my old girls had a tilted/twisted pelvis like Logan does now, and 99% of the time I had no idea she was in any pain at all.