When Can Puppies Start To Eat Canned Puppy Chow?

I recently bought a rottweiler puppy from a breeder, and she is AKC registered, a beautiful purebred puppy. Anyways, I wanted to give her a better choice of food, because right now she is eating Purina Puppy Chow, and I was going to add Purina ONE canned dog food for all ages into that, so she has better meals. OK, so she is a little over weight, the breeder over fed the puppies. I'm exercising her multiple times each day, and taking her on long 20 minute walks around the whole block for her to go potty, and so she can burn energy and calories. I truly love my beautiful puppy, and so far she has been sleeping with me in my bed at night. I just want to give her a better balanced meal. She is 11 weeks of age currently, and on February 11, she will be 12 weeks of age. Is she eligible to eat canned dog food now? Or when should I start to mix canned dog food into her dry puppy chow? HELP?! 10 points goes to the person with the BEST answer!!!