St. James's Palace has announced that Prince William and Catherine Duchess Of Cambridge are expecting a baby. (Chris Jackson/GETTY IMAGES)

So far, Duchess of Cambridge, you have avoided most of the booby traps of princesshood. Even when you’ve tripped, you’ve managed to keep the public rooting for you and your prince to restore some luster to the British monarchy.

You have managed in the last year to walk that line between belonging to the public and maintaining a healthy emotional distance from it. You certainly didn’t seem torn up or weepy when your privacy was invaded, you seemed appropriately angry.

Now, the palace has confirmed, you are pregnant.

Here’s where it’ll get tricky.

It's not about you or your image or even your bikini tops any more.

Your first priority will not be to anyone or anything other than your baby. You’ll know that, even if no one else in your inner circle gets it. This is not The Royal Baby, this will be your and William’s baby.

So, I humbly offer a few bits of advice:

● Don’t let anyone into your hospital room besides William for at least a few hours after the birth. It’s unrealistic that you might be able to block visitors for the full length of your post-delivery stay, but please do try to give yourself a few quiet hours of dozing together.

The memory of those hours can help you endure much and will last far longer than you can imagine now.

● You will have every adorable, fancy, state-of-the-art baby contraption at your fingertips. Know that you need none of them.

Most of them, like handsewn burp clothes, are harmless, some, like baby mittens, are helpful, but some are bound to get in the way. Be off with the nursery decor and the couture outfits.

And, remember, whichever stroller or designer onesie you choose, it will become an instant sensation. Please go for simple, affordable and useful.

●Don’t get caught up in the immense pressure to keep up appearances. You are a beautiful young woman who seems to be preternaturally pulled together. A baby may upend your grooming schedule.

Even if he or she doesn’t, perhaps consider going out once in a while looking disheveled. Trust me, your public will love you even more.

●Finally, I’ll leave you with the words of the twinkly-eyed Nordic grandmother who led my one prenatal baby care class. Her five-word send-off to us all has helped me through some rough spots. I think it could act as a talisman to you as you enter this next phase of ferocious public attention:

“Have fun with your baby.”

What advice do you have for Catherine, Duchess of Cambridge?