Carole Underwood admits to a few jitters before her daughter Carrie's Grand Ole Opry induction in Nashville May 10. "As a mom I was thinking, 'I hope she can hit that high note,'" she says, adding with a laugh, "'and I hope no one can see up that dress!'"

Mom can relax now. With Carole, dad Steve, sister Stephanie and niece Sarah in the audience, Underwood, 25, teared up during the ceremony, which included—yes—hitting the high notes with Vince Gill on "Jesus, Take the Wheel." "I'm still in awe," the new and currently youngest Opry member told PEOPLE. "It's the ultimate award." Especially when her trophy was presented by fellow Oklahoman Garth Brooks, a childhood hero whom Underwood first met when she was 10. "This is a marriage," Brooks told her of joining the likes of Loretta Lynn and Patsy Cline in the 83-year-old, 69-member Nashville institution. "No other award will last as long or be more important than this."

And like faithful spouses, Opry members have obligations too. "I've been here when [a performer] cancels and they call [Vince] up, and he was watching TV at home, and he's like, 'Sure, I'll come on down,'" Underwood reports. "I'm not home often right now, but there will be times!"