Amber and Alice by Janette Paul

When Amber Jones wakes up in her sister Sage's speeding car, with no idea how she got there (though the hangover is a clue), all she wants to do is go home. But Sage is convinced a road trip to Alice Springs will finally answer the burning question: who is Amber's father? Because nine months before Amber's birth, her late mother Goldie made the same trip.....