Kelly, who is due to tie the knot with talent manager Brandon Blackstock, chose a lace-detailed bridal dress with a sweetheart neckline for her appearance on US chat show, The View.
"Me and my bridesmaids... on The View. :)" wrote Kelly on Instagram along with a photo of herself in the elegant gown and her backing singers sporting matching lilac dresses.
"Just hanging out with my band... #EnjoyTheView," posted Kelly with another picture which showed the musicians dressed only in bow ties and jeans.
After performing her latest single Tie It Up Kelly revealed the plan for her upcoming nuptials to the show's hosts.
"We just got off tour so in a couple of weeks we're just taking the kids and doing something really small," said Kelly, referring to Brandon's children Savannah and Seth. "He has a 12-year-old and a six-year-old, and they're awesome.
"I really lucked out on that. I love it," added the American Idol winner. "They laugh at me. I love doing the homework, I love going to the games."
Kelly had previously hinted that her wedding would be a private affair in August when she said that the couple had talked about eloping.
"We are so busy that we finally just came to terms the other night and were like, 'So, we change our minds and we want to elope'," said Kelly. "We just got so overwhelmed by it – all the decisions."