So why did you adopt her in the first place? This makes no sense.
Since you adopted the child then simply left child with her parents while you took off to Canada, this may be seen as a strong case of adoption of convenience done solely to get the child to immigrate to Canada. You don't seem to have a real parent/child relationship with the child. I would predict very high chance of refusal here.
Plus if you didn't declare a legally adopted child in your own PR app, that would exclude them anyways from ever being sponsored for PR by you.