The glamorous redhead who brought groom Sidney Poitier home to meet the parents — when Mama was played by her real-life aunt (an Oscar-winning Katharine Hepburn) — has, in 43 years, quite naturally graduated to grandmother roles.

She plays one in “The Last Airbender,” a village elder who is the first to recognize the title character as the once and future avatar. “I’m in the first 15 minutes so if you miss the first 15 minutes, as my family did, of course — that’s families for you — then you won’t see me. But in that first 15 minutes, if you like nothing else, you might like the Greenland footage. The cinematography is really beautiful.”

And so is she, at 65 — Titian-haired as ever, with silver highlights. “I think M. Night Shyamalan is a fascinating director. I loved working with him. We got bad reviews, but we made $70 million the first three days into release. That’s good revenge.”

Billed ninth, Katharine Houghton is one of the few readily recognizable names in the cast. “I guess this is my tenth film,” she figures (accurately). “Guess Who’s Coming to Dinner” was her first — and “the one everybody knows, but I’ve done others — not as famous.” To name names: “Mr. North,” “Billy Bathgate,” “Ethan Frome” and “Kinsey.”

Despite the entre into movies that Hepburn provided for her, Houghton returned to the stage and appeared in 60-plus productions on and off Broadway and regionally.

— Harry Haun