The Hilton terms and conditions say:
Hilton Honors members must be the registered, paying and staying guest to qualify for on-property benefits. Member benefits are not transferable to any other individual.
Many hotels would grant the benefits to your wife in this situation, but she isn't entitled to them. If she herself is gold or diamond then that's a different story.
Otherwise you could book a room in your name and put anyone in the world as the second guest, and they could get diamond benefits without you ever turning up.