Nice job Cheryl!
Looks like Quinn has got the idea down!
I would say that I would probably try to work it with food, if possible. The reasoning is that because of the control elements within tug play, you have the potential to diminish your tug drive itself. Because of Quinn's age, I would be extra careful when incorporating obedience behaviors into play, making sure to keep your tug drive levels as high as possible.
The two ways around this are either working with food, or strapping Quinn up to a harness and having a helper frustrate her, and then rewarding her with a bite on the tug at the perfect moment.
Just some food for future thoughts!
Thanks, and great job with developing the barking!
Mark