Lindsay Lohan shows off new healthy curves post rehab... but sister Ali steals the spotlight with her alarmingly thin frame

She only moved into a new apartment in New York City on Tuesday.

But just days later, Lindsay Lohan was back in her old stomping ground Los Angeles - and back behind the wheel - as she took sister and new roommate Aliana out on a shopping spree.

Zooming around town in a white Mercedes-Benz convertible on Saturday, the siblings appeared not to have a care in the world.

Born performer: Lindsay Lohan held an impromptu photo shoot as she emerged from her car during a shopping trip in LA on Saturday

Someone's missed the spotlight: The actress, who usually detests the paparazzi, wore a broad smile on her face as she soaked up the attention following three months in rehab

After spending the last three months cooped up in relative seclusion as she undertook court-ordered rehab at Cliffside Malibu Treatment Center, Lindsay emerged from her car with a broad smile on her face.

Displaying her healthy new curves in a pair of barely-there pink shorts, which she teamed with a navy blue T-shirt, black and gold buckled boots and a long gold necklace, the born performer simply couldn't resist posing for the paparazzi.

Giggling as she posed with one arm behind her head, played with her hair and adjusted her dark sunglasses, the 27-year-old was clearly relishing the much-missed attention.

Showstopper: Despite her sister putting on quite a show for photographers, Aliana stole the spotlight when she exited the vehicle displaying her worryingly thin frame

All angles covered: The 27-year-old made sure to show off her new curves from every possible angle as she flashed plenty of flesh in tiny pink shorts, a loose navy blue T-shirt and black and gold boots

However, the Mean Girls star was soon eclipsed by her younger sister, as she made her own dramatic exit from the vehicle.

The leggy brunette had her worryingly thin frame on full display in tiny cut-off denim shorts and a lacy black backless halterneck top, with she wore with black ankle boots.

With her flat stomach and alarmingly thin frame, the teenager has drawn concern for her health and wellbeing.

Back so soon? The star only moved to New York on Tuesday, but was back in her old stomping ground just four days later

The 19-year-old, who is represented by New York-based Wilhelmina Models, has undergone a startling transformation in recent years as she pursues a career as a fashion model.
The close siblings have moved into an apartment together in New York's trendy Greenwich Village as Lilo rebuilds her career and reputation following her ongoing legal dramas.
But perhaps it's as much for Ali's benefit as her sister's.

Gone too far? The aspiring model has drawn concern for her health after dropping a significant amount of weight over recent years as she pursues a career in the fickle fashion industry

Worrying: With her tiny denim shorts and backless black halterneck top, the 19-year-old couldn't hide her stick-thin arms, protruding ribs and collarbones

The new digs reportedly have enough room for the actress's live-in sober companion as the star focuses on her sobriety, which she is said to be taking 'really seriously'.

So seriously in fact, that she pulled out of the European promotional tour for new film The Canyons on the advice of talk show queen Oprah Winfrey.

In a candid chat after wrapping the first interview with the star since her release from rehab, which is set to air on August 18, the 59-year-old convinced the troubled redhead the urge to drink bellinis in Italy would be too much to resist.