Hey there, Deborah.
Have you started implementing any of the tips Gem provided (working on counter-conditioning, rewarding good manners, tiring her out a bit before walks, etc.)? That’s where we’d recommend starting.
It may take some time to get some traction, but you should be able to calm her down during walks with some practice and persistence. And until then, use some of the management techniques Gem lays out.
Best of luck!

Interesting idea, Alice! Thanks for sharing.
🙂

I think the jumping is inciting the prey drive. The erratic and unpredictable behavior does incite prey drive. She seems to be ok until the little dog, Ditto, jumps around, inciting her prey drive; for you to stop a puppy from jumping around is nearly impossible and likely you don’t want to do that. The only way I see to solve this is to keep them separate in their own crates, and to have her on a tight leash when around the puppy. Might have to use the muzzle also as a precaution. Continue to work with her while using the caveats I have suggested. I’d also be sure to crate them both at the same time. The puppy needs crate training, so as hard as it might be, I’d also crate her to stop her circling and running around the puppy’s crate. I’d use treats when she doesn’t act on her prey drive, and teach her commands to stop any threatening behavior. The word No! Should suffice. Most important: Just as she says to keep the dog and cat separate when not supervised, I’d keep the puppy safe and separate when they aren’t supervised. Terriers bark and act erratic at times, so I would keep them separate even when supervised. Someone more experienced than I might be able to offer more options.