The intergenerational chick flick “Georgia Rule” allows Jane Fonda, as the tough but charming matriarch of the Wilcox clan, ample opportunity to toss wizened one-liners at Lindsay Lohan and Felicity Huffman. But when she tells Ms. Lohan, who plays her granddaughter Rachel, “For a smart girl, you’re good at stupid,” she hits a little too close to home.

Ms. Lohan made her name as an abnormally adept child actress in breakout remakes of “Freaky Friday” and “The Parent Trap.” Those performances were notable for their startling maturity, and later box office hits such as “Mean Girls” boded well for her transition to adult star. Since then she has amplified her headline status with crotch-baring paparazzi photos and unceasing nighttime exploits. Though she has matured into a striking young woman who often looks eerily reminiscent of a young Ann Margaret, Ms. Lohan has yet to prove her capabilities as an adult actress.

Starring opposite Ms. Fonda and Ms. Huffman, Ms. Lohan doesn’t always measure up. Rachel is a wild teenager sent to live with her grandmother, Georgia (Ms. Fonda), to be straightened out before shuffling off to college. Her mother, Lilly (Ms. Huffman), had her own antagonistic relationship with Georgia, and as Lilly seems to have retained her teenage hatred for her mother, it’s a bit difficult to understand why she thinks her plan for Rachel will work.

As Ms. Lohan has plenty of reallife experience playing a wild child with an ineffectual mother, the role of Rachel seems tailored for a startlingly truthful performance. Mark Andrus has written a script that could be saved by a hypersexualized tour de force, but Ms. Lohan fails to deliver. Her Rachel sashays into town as an overblown mess who has unfortunately fallen for her own hype.

A master of subtlety and wit, Rachel tells Hector Elizondo, a randomly placed Basque man she has just met, to relay a message to her new crush: “You tell Harlan that if he’s up for a little danger, I’d really love a ride.” To prove the intense intellect behind all the sexual bluster, she name drops. A quote from Ezra Pound receives the rebuttal: “That’s Ezra Pound. The poet.” At a younger age, Ms. Lohan impressed with her ability to master and reclaim hackneyed dialogue. Here, she is left at its mercy.

The script demands that her character charm and terrify the small town of Hull, Idaho, with her charisma and risqué sexuality, but Ms. Lohan inspires emotions that better resemble irritation, boredom, and disdain. She mugs for the camera at every opportunity, gallivanting in skimpy outfits and generally relying on her breasts to do all the heavy lifting in the role. While that approach may work with paparazzi, on-screen an actress has to do a bit more to get positive attention.

And she’s not the only one who flounders. Garrett Hedlund, who plays the small town’s heartthrob like an underfed puppy in need of a haircut, responds to Rachel’s mockery at his virginity with an incredulously absurd: “Have you had sex?”

Only Ms. Fonda transcends the script, imbuing a level of dignity to her repeated insistence on reciting “Georgia Rule” whenever anyone deigns to break an unwritten code in her home. She is so perceptive that it becomes nearly impossible to discern why Lilly hates her and has taken to drink as retribution. Ms. Huffman is her usual dependable presence on-screen, but the logic of her character remains difficult to distinguish throughout the film — as is her attachment to a disturbing Cary Elwes, who is almost too convincingly transformed into Rachel’s smarmy stepfather.

Director Garry Marshall may have helmed such box office hits as “Pretty Woman,” “Beaches,” and “The Princess Diaries,” but he was also the mastermind behind the painfully executed “The Other Sister,” in which Giovanni Ribisi and Juliette Lewis tastelessly frolicked as mentally handicapped lovebirds. Here, the broad swath of emotion that made Julia Roberts into America’s most loveable prostitute is unable to navigate the landmines of sexual molestation.

As Rachel attacks every male in sight with her unsettling attempts at seduction, she nonchalantly volunteers to a veterinarian named Simon (Dermot Mulroney): “I was 12 years old when my stepfather started having sex with me.” This irritating revelation has somehow been kept from her mother for five years. But did she even get molested at all? The story treads back and forth over this point for the majority of the film, trying to distinguish the lines among truth, fiction, trust, and deception just long enough for the Wilcox women to transform their rancor into love.

To what avail? All three women carry their emotional damage on their sleeves, but there is no time devoted to how or why they became so antagonistic and uncommunicative, nor why they never bothered to have a discussion about their grievances before this life-changing summer.

Instead of building a heartwarming journey toward redemption, “Georgia Rule” squanders the potential of its formidable cast and the wisdom to be garnered from small-town life. Worst of all, Rachel often comes off as a ludicrous twit, making everyone else look all the more foolish for falling for her tricks. “Georgia Rule” wants to be a smart, empowering movie about the bond of maternal love, but it’s just too good at stupid to get there.

mkeane@nysun.com