Roper is pregnant and expecting a baby girl with Tolbert, whom she married in January 2016.
Iaconcetti and "The Bachelor" producer Lindsay Liles were among those to share photos from the star's shower on Instagram.
"Jade is my first friend to ever be pregnant. I'm in total awe of this woman. She gets more beautiful inside and out everyday. #babyjanner," Iaconcetti wrote.
"Congrats @jadelizroper and @tanner.tolbert! I can't wait to meet Baby Janner," Liles added.
People reported Roper and her guests enjoyed a sit-down brunch at The Garland hotel in Hollywood, Calif. The party featured a bar with "poptails," or champagne with popsicles.
"I feel very blessed that all my friends and family were able to make it and take time out of their busy schedules to celebrate such an important time in mine and Tanner's lives," Roper told the magazine. "It could not have been a more perfect day!"
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