Hahahahahaha! I don't really know what the stand-stay command for you is, but it's generally the same movement as Sit huh? Maybe you could wean her off of Sit by only commanding a Sit verbally and use the hand motion as her free stack command. Or you could come up with something totally new. LOL, I can only imagine what you're going through!

No pics? I'm so excited for you! Good luck for all of Gracie's future shows/wins!

Edited to add: Some dogs are amazingly bright and catch on that the nylon buckle collar means Sit and the show lead means stack. Maybe Gracie will differentiate that in time.