HI
Unfortunately many of the good shops in Las Vegas have closed but Fabric Boutique is still there I believe
http://www.fabricboutique.com/
also The Christmas Goose
http://www.christmasgoose.com/
Quiltique is in Henderson if you can drive a bit
http://www.quiltique.com/
and Fiddlesticks in Boulder that is also a drive from the city center
http://www.fiddlesticksquilts.com/
Have fun exploring the shops!