Maybe it was crafty digital retouching or the products she and her fellow screen sirens are paid so much to endorse actually do work.
But lately I've noticed that Nic's contemporaries are not all faring quite so well (or not using the same CGI technicians, at any rate).
And as confronting as it is to look in the mirror and see the signs of ageing on your own face, I somehow found it was even harder to see them etched on the faces of Hollywood film stars who I've grown up admiring as the best examples of timeless, physical perfection.
When I was 14 I had my first boyfriend. I had a picture of him framed beside my bed and gave the picture a kiss every night before lights out.
His name was Tom Cruise and it didn't seem to matter much then that the kisses were never going to be returned or that I could see the creepy outline of Michael Jackson showing through the photo clipped from a magazine.
Eventually he got upgraded to Brad Pitt and I confess to having had a soft-spot for him ever since. And we're talking more than half my life, here.
But the purpose of lusting after an unattainable celebrity is that you have the luxury of imaging them as creatures of perfection, immune to the hum-drum realities that plague the real world, especially wrinkles and grey hairs.
Perhaps I was feeling sentimental or else it was just one of those strange coincidences but recently I found myself watching a series of new movies all featuring the A-listers of ... well ... not quite the past, but certainly what might be called 'enduring recent history'.
And you know what? They looked old.
Brad Pitt and Angelina may have been method acting rather too well in their film-flop By The Sea but it was more than a plot about a failing marriage that left them looking washed up. It was simply that they were getting old. And not just by Hollywood standards.
In another film, I was equally shocked to see George Clooney and Julia Roberts side-by-side, also showing their age in a suspiciously human way.
And although nothing will stop me indulging in yet another love story involving Colin Firth and Renée Zellweger, it was highly confronting when the latest Bridget Jones movie did a flash-back to the original film, revealing what 15 years does to a face even when you have all the money and makeup in the world to throw at it.
It's not that I think they should hang up their hats and give the blockbuster roles to fresh-faced pups, but I just wish somehow that the celebrities of my youth could remain as fictional as the characters they play and stay ageless in a such a way that made it more possible to ignore the impact time is also having on fans like me.
Because no matter what the reality, we're always 21 in our own hearts, provided we don't look at the mirror - or the movie screen - to be reminded otherwise.