It is most likely that Karen is suffering from body dysmorphic disorder.
People who have body dysmorphic disorder (BDD) can't stop thinking about their flaws for hours each day. They are unable to control their negative thoughts and do not believe people who tell them that they look good. They may feel so ashamed that they may avoid social situations. This disorder usually initially surfaces in adolescence and is primarily characterized by obsessive thinking about real or perceived personal flaws.
Karen looks in the mirror each day and was so dissatisfied with her looks that she went through 3 cosmetic surgeries, and will most likely go through more, just to never be satisfied.
I hope this helps!