I have to ask, why don't you let her go/stay outside when she's bored?
My dog LOVES to spend time outside and doesn't always have to go to the bathroom to want outside. She will sometimes stay outside for hours in the evening when I get home from work. As long as she's not barking and she wants to stay outside, I let her stay out since it makes her happy.
You could use that time to play with your kittens uninterrupted by the dog. That is, I guess, unless you have a situation where you have to take her out (no fenced yard).
Plus, a calm attitude and long, daily walks work wonders on energetic dogs. It just doesn't sound like a dog is the right pet for you, though.