By now you might be familiar with the story of Natalia Grace, and if not here's the quick version.
In 2010, US couple Kristine and Michael Barnett adopted Ukrainian-born girl Natalia Grace and believed she was a young child with a rare form of dwarfism.
However, the couple then alleged that Natalia was actually an 'adult sociopath masquerading as a child' and claimed that she had tried to kill them.
In 2012 they successfully petitioned to have her birth age put back from 2003 to 1989, meaning she would legally be recognised as an adult in her 20s, and left her in an apartment in Indiana as they moved to Canada.
That's the story of Natalia Grace, though since then there's been plenty of developments to fill in the details including more light being shed on how old she actually is.