If you have already formed a parent-like relationship with the child (meaning that you are the child's primary caregiver, pay for their clothing and education, child lives with you, etc.) - then I think chances are good that PR would be approved. I think it becomes a lot more challenging if you don't have this kind of relationship with the child. That's when CIC may flag it as an adoption of convenience that's been done specifically for the purpose of obtaining PR status for the child.