Kate Middleton was the bright spot at Queen Elizabeth II's annual summer garden party on Wednesday, May 22 -- in more ways than one! Dressed in a lemon-yellow coat dress and cream-colored bow fascinator, the seven-months-pregnant Duchess of Cambridge stood out from the crowd of other guests, who clamored for a glimpse of her growing baby bump.

PHOTOS: Kate Middleton's royal pregnancy style

And who could blame them? The mom-to-be's belly has definitely popped in recent weeks, and Middleton, 31, looked radiant. She appeared to be in great spirits as she mingled with her father-in-law, Prince Charles, and his wife, Camilla, Duchess of Cornwall, who wore a printed ivory and gray coat with a matching feathered hat for the occasion.

All eyes were on the expectant royal as she made her way around the elegant fete, smiling and chatting with other festively outfitted partygoers. Among the 8,000 invitees were Olympians, Paralympians, and officials from London 2012. Together, they are expected to drink more than 270,000 cups of tea and eat some 20,000 sandwiches and slices of cake.

PHOTOS: Kate Middleton's motherhood prep

After the playing of the national anthem at 4 p.m., members of the royal family split up to greet guests, each taking a different route through the grounds. Middleton attended for the first time as Prince William's wife in 2012.

The Queen's garden party is the pregnant Duchess' first official engagement in quite some time. She has been lying low in recent weeks as she prepares for the July birth of her first child.

Some of that time has been spent taking cooking classes from her new housekeeper, Antonella Fresolone. As Us Weekly reported earlier, Fresolone -- previously employed at Buckingham Palace, where she was known for her "delicious" Italian cooking -- is teaching Middleton how to make a number of new dishes in the small kitchen at Nottingham Cottage.

PHOTOS: Look back at Prince William and Kate Middleton's first year of marriage

The Duchess has also been devouring parenting books. "She is fascinated by the life growing inside her, and she is full of questions," a family source told Us earlier this month of the soon-to-be first-time mother. Added Graham Butland, of Hospice Charity Each: "Kate really engages with children. She's a natural. She's going to be a great mum."

This article originally appeared on Usmagazine.com: Kate Middleton Plays Up Pregnant Bump at Queen Elizabeth's Garden Party: Pictures