@hawkeye10,
My one step daughter were brought in from Canada when she was two weeks old and my wife decided not to apply for US citizenship for her adopted daughter as a child but instead leaving it up to her when she reach adulthood instead to do so if she wish to.
She is and always had been as must an American as anyone else except in the legal sense of the term but if there had been some error in the paperwork bringing her here as a two weeks old you would be for deporting her to Canada!!!!!!!!!!
As people tend to do she did not even think about not being a citizen in the legal sense into adulthood and in fact it was I who pointed out after 911 that she should get that citizenship paperwork because for example right after 911 had she been over to Canada shopping she could not had return home as the borders had been close to all non-US citizens and if she ever would get into any trouble with the law she could be deported and so on.
She is now a legal US citizen but in fact she had always been an American.