Lohan sported a denim dress and blue pumps, and wore her blonde hair pulled back in a bun; Ronson had on a black T-shirt and a gray skinny jeans and vest - she usually incorporates a hat into her rocker look, but this time she opted to show off her pixie haircut.
They stood up for a standing ovation when Charlotte Ronson appeared on the runway after the show, and made a quick exit as media chased them backstage (where they hid in a VIP lounge).
Actress Emma Roberts, the niece of Julia Roberts, joked that she was stuck in a "Lindsay traffic jam" as she tried to leave the crowded event.
In-demand music producer Mark Ronson - brother of Charlotte and Samantha - deejayed the music at the show.
He declined comment when asked about the buzz over Lohan and his sister, but said he was proud of his family.
"I think we're just all driven and love what we do," he said of his siblings.
