The singer also teases what to expect from her performance with John Mayer on Sunday.
The 30-year-old singer wowed on the red carpet, wearing a beautiful silk lavender dress lined with silver crystals. "It's Dolce & Gabbana, custom," Morris, who welcomed her first child, son Hayes, last March, told ET's Keltie Knight. "I saw the sketch and it reminded me of the roaring '20s, and I feel like we are back in those again. So, it's going to kick it off the right way!"
For her beauty look, Morris sported sleek hair with subtle waves, smokey eyeshadow and a nude pout. She topped everything off with a pair of dazzling teardrop Peach Morganite LeVian earrings and a Kallati ring.
Later on Sunday, Morris will be taking the stage to perform her hit track, "The Bones," which is nominated for Best Country Song. John Mayer will be joining her for the performance, and Morris teased what fans can expect while chatting with ET.
"He is amazing, I have been such a fan for a long time," Morris gushed. "But he has really always been supportive of me. We actually met at the GRAMMYs here a couple years ago and we have just had this mutual respect for one another and our craft."
"When I got nominated this year and was going to be performing, I just reached out as a friend to John and was like, 'Hey, will you come in and sit in on guitar?'" she recalled. "He graciously said yes and he has just elevated this song to an even higher level than I thought. I am just so grateful that he said yes."
As for the actual song, Morris said it's been "such a beautiful journey," from the very beginning of writing "The Bones," to seeing it receive recognition at the GRAMMYs.
"To end it here, because it is sort of the end of the single cycle, ending at the GRAMMYs is a pretty damn good place to end it," she said. "My favorite thing is, I wrote it about a relationship, but then so many fans during the beginning of COVID-19 were saying, 'This song reminds me of our world right now.' When the bones are good, the rest don't matter ... we are in the trenches together."
The 63rd GRAMMY Awards air Sunday, March 14 at 8 p.m. ET/5 p.m. PT. Follow along right here at ETonline.com for everything you need to get ready for the annual awards show, including how to watch the GRAMMYs, GRAMMYs performers, Best Dressed stars and more.