Katie Couric is preparing to become a first-time grandmother.

The 66-year-old TV host's eldest daughter Ellie Monahan, 32, is pregnant and Katie was told in a very special way as she was presented with a custom-made friendship bracelet emblazoned with the words "Granny to be" as the pair headed to a Taylor Swift concert with her other daughter Caroline.

Katie shared a video of the moment she was handed the bracelet on Instagram and wrote: "Been dying to tell you. This is what happens when you go to a @taylorswift concert last summer and forget your friendship bracelet and your daughters say, 'Don’t worry, we made one for you!'"

In the clip, Katie was seen trying to decipher the letters on the bracelet, saying: "Brand, brandy, B, granny …" before realising it actually spelled out “Granny to be."

Katie then appears shocked as Ellie tells her: I'’m pregnant" and the TV star replies: "You are?. Wow."

The former 'Today' show star went to see Taylor Swift perform at the SoFi Stadium in Los Angeles in August with her girls Ellie and Caroline, and she lavished praise on the pop star in a post on Instagram after the gig.

She wrote: "All I can say is WOW. @taylorswift defies superlatives. But let me try. She’s a brilliant singer-songwriter and mesmerizing performer.

"Oh, and did I mention she is indefatigable? I hope you enjoy watching some of the highlights This was a once in a lifetime experience I’m so glad I got to share with my girls who each have a PhD in Swiftology. They know every word to every song and every designer Taylor was wearing. We felt so lucky to experience this together. "

She added: "What I really loved is the joy Taylor exudes and the love she has for her fans and her entire team. But at the same time she remains so humble and grateful. Thank you Taylor, I don’t know how you’re going to do five more shows but I have no doubt you’ll kill it night after night."