I have not seen the movie, but I believe I heard last year that she carried a Hogan Shopping bag in the movie. I have one in brown if you want pics.
EDIT. Sorry, Hogan WEEKEND...I always get those two mixed up. Here is a pic. www.styledrops.com has one for around $900. I have purchased from them AND from the Hogan flagship store, and they are authentic.
Thank you for your response. While Ms. Simpson definetly has a purse fettish none of her purses are the one. I am on a mission it was an awesome bag!!!! I'll keep you posted!!! Lol... ...gotta have it...
She also carried another white bag in "real life" by Hogan...and they have this one as well as a smaller sized version. I will attach a photo. This was called the "Lizzy" but also goes by "Horse." Hogan tends to have multiple names for its larger bags.