Ashlee Simpson is only 22 years old, but already she is dealing with plastic surgery questions fit for a person twice her age.

The singer and actress has changed her entire appearance since finding fame - going from a dark haired punk princess to a more Hollywood-friendly Californian beach babe. She may have even changed her nose and chin somewhere along the line.

But whether she has or has not had plastic surgery, the youngest Simpson sister says she is happy with how she looks.

Speaking to Harper's Bazaar magazine, she says, "I don't get bothered by people saying what they say. I'm a happy person, and I'm happy with my looks."

Ashlee, who is dating Fall Out Boy's Pete Wentz - a man who loves to wear make-up - has not formally admitted to going under the knife but refers to her looks as before and after.

She continues, "I loved how I looked. I'm not an insecure person, nor was I before... I believe if somebody chooses to do plastic surgery, it [should be] for yourself, not for anyone else."

Despite her dramatic change in appearance, Ashlee continues to emphasize the importance of self-esteem.

She says, "Everybody always has an opinion. One minute they'll love you; one minute they'll hate you. When you go home to sleep at night, [the important thing] is to feel good about yourself. And I do."

But is she trying to look like Jessica - the older, blonder, bustier sibling? According to Ashlee, who does bare an increasingly similar resemblance to Jessica, no.

She says, "Of course I look like her. She's my sister. It's like, God, please! We think it's quite funny."