I have what at least used to be called "Ultra King Kong." It's the black color, which is harder than the red, and it's the largest size.
It depends on your particular Dobe of course. If she needs something softer, get the red colored one. If the largest size is too big at this stage, get a smaller one.
You call her a lunatic though, so it sounds like you could save the money and go straight for the big black dude.