At the Abbey Dawn New York Spring/Summer 2012 collection during New York Fashion Week; Kim, Khloe and Rob Kardashian cheered for their little half-sister Kylie Jenner's catwalk debut.

The 14-year-old Jenner was dressed in a black ballerina collection by singer-designer Avril Lavigne at the Style 360 in New York City.

And in case you are wondering how Jenner landed with this opportunity, Avril has been dating Kylie's brother Brody Jenner.

Check out the images of the Abbey Dawn New York Spring/Summer 2012 collection and Kylie Jenner's catwalk debut below: