The model mom, 42, posted a sweet tribute on Instagram Thursday in celebration of son Benjamin Rein's 13th birthday ... a new teenager in the house ! Happy birthday my sweet angel!

"Happy 13th birthday, Princess Estelle!" before tagging the photographer, Kate Gabor. Royal fans quickly flocked to the comments section to share their well-wishes. One penned: "Warmest birthday ...

Hilary Duff lists some of the best things about son Luca in touching post On March 20, Hilary Duff marked her son Luca Cruz’s 13th birthday ... Hilary Duff Wishes Son Happy Birthday With Tear ...

John Travolta posted a sweet message for his and his late wife Kelly Preston’s eldest son Jett Travolta on his birthday 17 ...

And her 13th birthday is coming up next month ... one they can share and protect for as long as they live — the memory. Happy birthday, Piper. I hope 13 proves as lucky for you as it ...