[mommy of 3]

I have a 2 yr old rotti that came to me extreamly overweight, she has now lost alot of that weight through proper diet and excersise. But we still have about 20 lbs to go. With this weight loss has come a new found energy for her, her joints are recovering and she doesnt limp anymore. I was told a good way to release some of this energy is to start her working. Doing some of the things rottis were bred to do, and get her to use her instincts. I am not looking to compete just excersise. Does anyone have any advice as to what the best way to do this is? Or does anyone know if there are trainers in the central alberta area that i could take her too? I was thinking herding maybe, my mother has a flock of sheep at her property so it would be easy to practice, but i dont want to just throw her in and say "have fun" lol. Thank you
Melissa