Strangers with Candy (1999)

Jerri Blank is a 46-year-old "boozer, user, and loser" who tries to put her life back together. The reformed runaway and addict returns to high school as a freshman, where she tries to fit in and act hip with girls 1/3 her age. Unfortunately, she hasn't quite shed her immoral background or acquired any ethics, and her bizarre family and frustrated schoolmates have trouble interacting with her.