No thank you very much.
100 % NOT real. Secretarial. Sorry to say.
The signature is 100% secretarial.
If I'm not mistaken, this is souvenir menu from Las Vegas Hilton Hotel (1975) and even with this secretarial signature it's cost about $150-250 on eBay (depends on condition of the menu). So this is good news for the owner of this item :)
Good news? Well that depends on how much Susanne has paid for it (if she has already bought it), or just wants to find out about the authenticity in advance.
No good, and I dont think the menu is really that rare unlike like the early Vegas ones from 69-72