We have no idea but Ann would have known that Lolo would have been given custody in the event of a divorce and she could have taken care of the matter when she was in Hawaii in 1971.(The marriage was already almost over when Maya was born) Maya did return to Hawaii to attend Punahou when she was 14, before then she either accompanied Ann while she was conducting field research or she got dropped off to her paternal grandparents.
The problems began when an interview was conducted with both Barack and Maya and they gave the name of Queen’s Hospital as being where he was born. In an interview a couple of years later the name of another hospital was given.
How far back do the two Hospitals mentioned keep records?