The Evolution of Ashlee

Ashlee Simpson has changed … more than her hair!

No longer the angst-ridden 20-year-old the world knew in 2004, Ashlee is back with a new album, "Bittersweet World," and a sweet new outlook on life. "I have great friends, great family, great boyfriend, great career and awesome fans," Jessica's lil' sis told "Extra."

Ash also dished on what she rarely speaks about -- her boyfriend, Fall Out Boy bassist Pete Wentz -- and Jessica's tabloid-fodder relationship with footballin' boyfriend Tony Romo.

To hear more of Ashlee's latest single "Little Miss Obsessive," check out