Dance won't sit straight for me. She always sits off to the side a bit, and when we're practicing fronts, she's not perfectly straight either and then falls over onto her hip (lazy sits). How do I correct this? I click and treat every time she does it right, but she seems to think that as long as she's sitting, she's good. I've never really cared if past dogs did this or not, but since I want to get into OB and Rally with her, lazy sits just won't do. Any help would be very much appreciated!