What is the movie with Julia Roberts in Material Girls?

In the movie Material Girls with Hilary and Haylie Duff, they are watching this movie while ironing. I know Julia Roberts was in it, and I want to know what the name of the movie was. They commented on what a good push up bra could do, and then Tanzie used the idea from the movie to get some information. Does anyone know if that was a real movie Julia Roberts was in and what it's called?