After already mastering hits by Nicki Minaj, Alicia Keys, and Keri Hilson, British cousins Sophia Grace Brownlee and Rosie McClelland have added a Taylor Swift song to their repertoire with another memorable performance on the "The Ellen DeGeneres Show."

The pair -- who have been traveling to promote their new book Tea Time With Sophia Grace and Rosie -- sang Swift's "I Knew You Were Trouble."

In keeping with the theme of their previous performances, Sophia Grace did the lion share of the singing while Rosie focused primarily on carrying out choreographed dance moves beside her. (That said, homegirl has definitely upped her game. You go, Rosie!)

Since rising to fame in 2011 by way of a viral home video, the young cousins have had quite a ride. In addition to taking the stage on "Ellen" multiple times, the girls have met a host of celebrities on the show. They sat for tea with Taylor Swift last February and had a few good laughs with Russell Brand last spring.

On top of those appearances, the cousins were invited to interview celebrities on the red carpet at last year's Grammy Awards and they were honored at the Teen Choice awards as well.

While Sophia Grace's father told The Huffington Post's Lisa Belkin that she can be somewhat shy and quiet, the young star showed no signs of discomfort while on the stage.

When DeGeneres asked Sophia Grace if she was nervous while singing the Taylor Swift song, she promptly replied, "No, I love it. I want to do it again."