Willow

The other Knowles sister (not Beyonce) went all superbitch on a local Las Vegas anchor today -- showing the world she's not only Beyonce's younger sister, but she's also the dumb one.

During a commercial break, the anchors on KVVU asked Beyonce's little sister and her rep if they could mention Jay-Z during the interview. The rep shot them down -- wanting the focus to stay solely on Beyonce's little sister-- and the station agreed.

But dammit if Beyonce's little sister didn't go off on the anchor anyway -- on live TV. Ring the alarm!

Source TMZ