I booked 2 rooms for an upcoming family trip over Xmas in a few cities. My sister and her husband will be arriving a few hours before me and my wife - they do not have status with Marriott. Are they able to check-in early, at around 1pm, without me being there?

My ambassador replied saying that "platinum benefits are not transferable to guests" - does this mean my SNAs and early check-in / late check-out will not apply to them? If so, this will be very frustrating to manage...