I should have spoken more precisely, by bad plastic surgery I mean bad cosmetic work in general.
To me it looks like she's had collagen injections. If you look at pictures of her from the '80s and early '90s, she always had beautiful high cheekbones -- amazing bone structure. Now she has chipmunk cheeks. Her lips are also as full now (if not fuller) than they were when she was in her '20s. That's not normal -- lips thin with age.
But really, the main problem now is that her hair and makeup does her no favors. If she went darker with her hair (not necessarily dark brown, but definitely not bleach blonde), went for softer makeup (which is always a good idea as one ages), red or rose pink lipstick instead of nude lipstick, and found a hairstyle that flattered her, she would look SO much better.
I almost feel like she wants to make herself look ugly on purpose. It's as though she got tired of being known as a great beauty and so purposely seeks out unflattering hair and makeup.