Credit: SPW/Splash News Photo: A Frail Looking Ali Lohan Goes for a Drive on April 24, 2012

While Lindsay Lohan may finally be getting her act together and focusing on her career, younger sister Ali has been the subject of recent criticism, thanks to her shrinking waistline.

Ali, 18, was seen driving to L.A.’s trendy Chateau Marmont on April 25 looking alarmingly thin behind the wheel of her car. Even with a sweater, Ali’s collar bone looks pretty pronounced.

Credit: SPW/Splash News Photo: Tiny Ali Lohan Gets Behind the Wheel of a Car

The younger Lohan sister’s dramatic slim down even has experts saying that she is “definitely showing signs of malnutrition.”

Sounds like Ali could use a few pointers from her older sis, Lindsay, who, in recent months, has begun to put her troubles aside in an effort to focus on living a healthier life.