Complex sentence: She was a cheerleader in high school and worked at a optician's office, before entering the adult film industry in 2001 at the age of around 20; since then, she has appeared in over 300 movies.
Split into simpler sentences: She was a cheerleader in high school and worked at a optician's office. She entered the adult film industry in 2001 at the age of around 20; since then, she has appeared in over 300 movies.