Foo Fighters rocker Dave Grohl's wife Jordyn Blum is pregnant and expecting their third daughter, a source confirms to Us Weekly. Credit: C Flanigan/Getty

Three little princesses of rock! Foo Fighters and Nirvana rocker Dave Grohl is expecting his third daughter with wife Jordyn Blum, a source confirms to Us Weekly.

An insider tells Us that the third-time mom-to-be has been struggling to come up with a name for her third daughter because she already used the names she liked with her eldest girls.

Grohl, 45, and Blum, who wed in 2003, are already parents to daughters Violet, 8, and Harper, 5. The rock musician has passed on his love of music -- especially for the Beatles -- to his daughters.

During the Feb. 9 CBS special, The Night That Changed America: A Grammy Salute to the Beatles, Grohl performed a cover of "Hey Bulldog." Before he started playing, Grohl told the audience: "I can honestly say that if it weren't for the Beatles, I would not be a musician. From a very early age, I loved their groove and their swagger, their grace and their beauty, their dark and their light. The Beatles knew no boundaries and in that freedom they seemed to define what we now know today as rock and roll for my parents, for me and for my daughter too." 

"The song I'm proud to play with these great musicians, from the 'Yellow Submarine' soundtrack, is not one of the Beatles greatest hits, but to me, it's a quintessential Beatles rocker," Grohl, who won a Grammy with Paul McCartney at the 2014 awards for Best Rock Song, added. "Paul's rolling bass line, the trademark Ringo drum fills, George's gritty distorted guitar and that sound that only the back of John Lennon's throat could produce. This is for my Mom's favorite band, my favorite band and now my daughter's favorite band."