Good luck with the adoption ! I would imagine if she is developing at the right pace right now that would indicate that she does not have cognitive issues. There really is no way to way to tell if she will or will not develope a learning disability in the future as that is usually not diagnosed until children are older and in school. Even if she were to ever develope a learning disability there is no 100% way to tell if that is just how things work out or if it has to do with her birth mothers diet. I have a cousin who seemed very up to speed until he was about two. Today he is in special education classes. His mother and him do not have PKU, so it was not PKU related at all. My point is that anything can happen and nothing is ever for certain. Like I said I would say that she sounds like she is doing wonderfully. Try to focus on the now and here and if issues occur as she gets older I am almost certain you will be able to overcome them!