By Rita Kokshanian
Updated Mar 21, 2016 @ 1:30 pm
Credit: Chris Jackson - WPA Pool / Getty Images

It seems that every time we think Prince George couldn't possibly get any cuter, he goes and proves us wrong. Mom Kate Middleton recently sat down for her first interview since her engagement to Prince William in 2010, and she revealed that her 2-and-a-half year old son has a pretty sweet nickname for his great-grandmother, Queen Elizabeth.

"George, at two-and-a-half, calls her Gan-Gan," the Duchess revealed. Aw! It seems that Queen Elizabeth, who will be celebrating her 90th birthday next month (with official celebrations to take place in June), has a soft spot for both Prince George and his younger sister, Princess Charlotte. "She always leaves a little gift or something in their room when we stay. That just shows her love for her family."

Middleton added that Princess Charlotte, the Queen's fourth great-grandchild, has a very special place in her heart. "It’s very special having a new little girl. I feel very, very lucky that George has got a little sister. The Queen was really thrilled that it was a little girl, and I think as soon as we came back here to Kensington [Palace] she was one of our first visitors here."

The interview, which is part of ITV's Our Queen at 90 documentary celebrating the monarch's momentous birthday, airs this Sunday, March 27, in the UK.