You need to be careful making the reservation this way. The hotel may ask that you, the member, come to the front desk before any benefits are given.

They are not entitled to benefits. Benefits are for the member staying in the room. The hotel may give it to them by mistake, or as a courtesy, but are not obligated to.

Do it the correct way. Call Hilton make the award reservation under their name. That way there is no confusion and your parents may avoid the embarrassment of being told you are suppose to be there since you are on the reservation.