Ali Lohan Models.... But Lindsay's BOOBS Steal The Show!

Lindsay Lohan is a big supporter of her lil' sis Ali's new modeling career ... but it was Lindsay -- and her boobs -- who stole the show yesterday at Ali's fashion show in NY.

19-year-old Ali was one of the featured runway models at the Wendy Nichol fall fashion show in SoHo ... a show that seemed to combine Lord of the Rings chic with a goth funeral.

Lindsay wasn't involved in the show -- but dressed the part anyway, sporting a low cut number that highlighted her Baggins (LOTR joke!).