The Truth and Lies of Ella Black by Emily Barr

Ella Black seems to live the life most other seventeen-year-olds would kill for . . .
Until one day, telling her nothing, her parents whisk her off to Rio de Janeiro. Determined to find out why, Ella takes her chance and searches through their things.
And realises her life has been a lie.
Her mother and father aren't hers at all. Unable to comprehend the truth, Ella runs away, to the one place they'll never think to look - the favelas.
But there she learns a terrible secret - the truth about her real parents and their past. And the truth about a mother, desperate for a daughter taken from her seventeen years ago . . .