Only a few years ago, Aliana "Ali" Lohan was trotting onto the sets of her big sister's movies and cuing the cuteness for Toys "R" Us and Little Caesars Pizza commercials.

Now, the 14-year-old is baring her cleavage, auditioning for pornography directors and allegedly causing scenes at parties -- all in one week.

First, the littlest Lohan was spotted wearing a face full of makeup, a low-cut top and what was probably the result of a well-built push-up bra. Then E! online reported that Ali and her mother and reality TV partner-in-crime, Dina, started a skirmish when asked to change tables at the "Sisterhood of the Traveling Pants 2" premiere party, causing them to leave.

On Wednesday, Us Weekly magazine reported that in the season finale of "Living Lohan," the 14-year-old auditioned for a horror movie directed by Peter Davy, not knowing that his claim to fame includes adult flicks such as "Voodoo Lust" and "Dreams in the Forbidden Zone."

Ali's never denied her love for the limelight.

"I grew up watching Lindsay, and it made me want to do what she does," she told Teen Vogue earlier this year. "Just the whole vibe. Being there, being on camera, or onstage, with everybody listening to you ... It's so cool when people look up to you.

"I want it so bad," she said of fame. "So bad you don't even know. And now, it's actually happening. I've already been asked for my autograph, and it's just a really good feeling to have."

But it seems her hunger for fame may be leading her astray. Is it only a matter of time before Ali's getting busted for DUIs and checking into rehab like Lindsay?

"Train wreck seems to be the route to fame in that family," said a celebrity PR executive, who spoke candidly on the condition that his name not be used. "Ali's following in her big sister's footsteps."

It's no surprise. Younger siblings look up to older siblings, especially when that older sibling is making millions of dollars and incites fan frenzies and paparazzi mobs when she goes out in public. But Ali didn't start out on her big sister's path to stardom. Instead of movies, she made her first full-scale foray into Hollywood with an E! reality show that chronicles her efforts to make a name for herself in the entertainment industry.

It's a formula that's worked before: Jessica Simpson's little sister, Ashlee, broke out by starring in her own MTV reality show, which followed her as she began her music career. But Ashlee was 20 at the time: Constant camera presence can damage a younger, more impressionable star.

"When you grow up in front of the camera and you're young, you just want to please the adults around you. That trumps all the natural developmental stages a child should go through," said psychoanalyst Bethany Marshall. "Your sense of self gets fused with the fact that you're playing a role. When there's no more role, there's no sense of self. That can leave you empty, unable to self-regulate and vulnerable to substance abuse."

Substance abuse is a problem that runs in the Lohan family. Dad Michael has one DUI, and Lindsay's racked up two. It may be enough to make a kid think that drinking is part of the fast track to fame.

"Lindsay's gotten so much attention for the negative that it makes sense that Ali might try to do the negative things as well," said Us Weekly's Aimee Agresti.

But Lindsay's got something Ali doesn't: Street cred. Despite her mess-ups, she's widely regarded as good at her craft. Meryl Streep, who worked with Lindsay on "A Prairie Home Companion," told Fox News her co-star is "a fantastic actress." Jane Fonda, who starred with Lindsay in "Georgia Rule," gushed that she's "so talented" to Access Hollywood.

Unless industry bigwigs start showering Ali with similar praise, she may self-destruct to get attention, resign herself to reality TV fame, or both, insiders say.

"Eventually, Lindsay will probably get her stuff together and won't fall off the deep end. Friends of mine who cast movies, if they weren't so worried about insuring her, they'd be all over her," said the PR exec. "But the question with Ali is, Does she have real talent like her sister? Plenty of people can leverage a family relationship, the question is, Can you deliver? And then, what does she deliver on? Does she deliver on true talent or just being a reality TV freak show?"