But she’s sprawled out half dead on the bed — we see only her hand float up in protest as he coos words of devotion and finally breaks into song. When the kindhearted, wrongheaded Republican New Yorker finally leaves their home for his fateful ski trip, she’s still buried under the covers.

The opening night audience had no way of knowing that “George is Dead” would fail to come fully alive until three scenes later when that woman, played by “That Girl” Marlo Thomas, was unveiled in all her glory. If we had known that the sleeping socialite would be so funny, that she would emerge fully formed to save the play, we might have shoved the old feller aside and roused her by any means necessary.

Thomas is a torrent of fresh air as the airhead Doreen, a pampered ditz who is is tucked, lifted and Botoxed to within an inch of her life. When George buys the farm in Aspen, having failed to buy Doreen’s heart, she becomes the most unprepared widow ever.

Boring and annoying in life, George is a real bother to Doreen in death. This infantile woman couldn’t arrange a bubble bath by herself and now she’s expected to make funeral arrangements. Might as well ask her to cure swine flu while she’s at it.

Freshly single, she’s already dreaming of finding a real husband when she shows up unannounced at the modest downtown apartment of Carla and Michael, a couple on the verge of a bitter breakup.

Doreen, perpetually lost, is drawn to Carla because Carla’s mother was her nanny years ago. After making note of their shabby place, so small and cozy, she asks for a bite to eat. Cheese would be lovely, brie if you have it. Presented with a platter of crackers and American slices, she can’t help but notice that the saltines are super salty. Would you be a dear, Carla, and scrape them for me?

Carla, perpetually tired, is played by Julie Brothers, whose slack-jawed expression, meant to signify mortification at Doreen’s behavior, must have calcified in an early version of the play in San Francisco. Would Carla really be so shocked that Doreen remains presumptuous, patronizing and wrong?

Now playing nanny to her helpless mother, whose own mothering was limited to paying customers, Carla’s daughterly devotion is a source of tension in her marriage, and so is Carla’s mentally ill brother, who uses his sister like an ATM.

Her liberal husband, a history teacher who prefers helping others by sitting on committees, is played by Reese Madigan, an actor who does his best to create a character from a string of zingers and snide one-liners.

Performed in 90 minutes with no intermission, “George is Dead” has regular flashes of wit, but it doesn’t grab hold of your emotions like it should. When Carla’s mother shows up to do some mothering (of Doreen, naturally), the dialogue is both overwrought and underdeveloped. A final scene at a funeral home feels tacked on and pointless. But it’s the giddy abandon of Marlo Thomas, her raspy voice like an old friend, that sends the play into low-level comic orbit. Along the way, she finds moments of touching self-awareness in a character built mostly for laughs.

Thomas is capable of much more, as she demonstrated playing another sort of socialite in the national tour of “Six Degrees of Separation.” In a role that earned Stockard Channing nominations for a Tony Award and an Academy Award nomination, Thomas was second to none, nailing every melancholy nuance of John Guare’s 1990 play. Until Doreen’s doozy of an arrival, “George is Dead” treads comic water — George finds common political ground with the Dominican driver (Carman Lacivita) taking him to the airport, and another scene establishes the relationship between Carla and Michael.

Directed by the playwright, whose screenplay for “Heaven Can Wait” was Oscar-nominated three decades ago, “George is Dead” is not a dud, but it feels like it’s not done.

One hopes that May, a writer with smarts to spare, bulks up the play with added layers of meaning. Perhaps Don Murray’s unfortunate performance as George will prompt her to rethink the title character and hit upon a more enticing opening and a more satisfying ending.

The good news is that even a half-baked comedy from Elaine May is pretty delicious stuff.