Rachel, 42, was joined by friends and family for the outdoor celebration, and pictures revealed that the tables at the soiree were decorated with gold, bronze and silver balloons spelling out 'boy'.
With just one month to go until the arrival of her second child, Rachel looked radiant in a black maxi dress – a look she has championed for much of her pregnancy. She accessorised with chunky gold jewellery, round black sunglasses, a black leather jacket and a slick of red lipstick.
Rachel and her husband Rodger Berman are already proud parents to two-year-old son Skyler Morrison.
And, depending on his mood, the little boy is excited about becoming a big brother.
"You know what? I'll get back to you on that!" Rachel joked to People back in October.
"It depends what day you ask him. Right now he just doesn’t want anyone near Mummy except him, so I don't know when that should change."
"I am in good spirits because being pregnant in the biggest blessing in the world," she continued. "I'm the luckiest person in the world."
Part of what makes the experience so special for Rachel is being able to share it with Rodger.
"We've been together 22 years, so he's my best friend, my business partner, my husband and the love of my life," she said.
"There's no one I trust more on the planet. There's no hidden agenda other than me being happy and doing what I love. From the very beginning, he was my biggest cheerleader – him and my dad."