She's 63, and she looks amazing! So do her daughters. So I'm guessing it's in the genes (that's my story and I'm sticking with it!)
For those of you who don't remember, Christie Brinkley is Billy Joel's ex-wife. She was in Billy Joel's "Uptown Girl" video... and a few years ago, he sang it to her at Madison Square Garden. There's even a peak back at the original video from 1983!
Alexa is their daughter. No word from Billy on what it's like to have his ex and his daughter on one of the SI Swimsuit covers!