Yes she is.
The proof comes in Astonishing X-Men #1 where the X-Men react to an attack on the mansion by a bunch of crazed sentinels.
So let's see. Hmm. Cyclops unleashes an optic blast, Beast strips for action, and Kitty Pride? Errrm, she phases through a chair.
Woo! That'll scare those pesky 50 foot mutant killing robots.
Lame I tell thee, lame.
PS Have you any idea how much codeine I had to take to get up and scan this image?