Kelly Clarkson is feeling the pressure to put on a perfect children's party after attending John Legend's daughter's birthday bash.

The Because of You singer was on the guest list as her fellow The Voice coach's eldest Luna celebrated turning five with a lavish event over the weekend.

As her daughter River will be seven next month, Kelly is now thinking about how she can match her celebrity pal's extravagant efforts.

"On the way out, I was like, my daughter's birthday is next month, so thank you for the bar that was just set," she told Entertainment Tonight. "There was a pony, a mermaid!"

"River was taking notes," John added, laughing.

Speaking to Extra, Kelly added: "He's raised the bar, which has totally screwed me. What am I going to do...? I already asked (John's wife Chrissy Teigen) who helped her with that party."

The Ordinary People singer then warned Kelly never to attend a party thrown by Kylie Jenner, as he added: "They created an amusement park."