Which child should get there own room?

Ok me, my wife, her 4 year old boy and my 2 are going to France and we have rented a house there but there is only 3 bedrooms, one with a bunk bed and one with a double bed. My son who is 14 and has autism, he is also 6 foot 4 so I doubt he would fit on a bunk bed but my daughter is 12 and my wife thinks she needs her privacy. Who should get there own room??