I'm looking for suggestions for a harness for Ada who is about 13lb. I want to start running with her and don't want her leashed to a collar because she hasn't yet found the difference between jogging and running in the park and tends to pull a bit. Looking for one that doesn't roll to the size, but stays in place nice. I've used Comfortflex and Canadog harnesses for Leo, but didn't know if there was something better for a smaller dog.