Keith Urban and Nicole Kidman certainly love to share their sweet moments on social media with fans, and Saturday (Dec. 28) was a particularly special day for the couple. Their youngest daughter, Faith Margaret, celebrated her 9th birthday.

Kidman marked the occasion by posting a precious throwback photo of herself holding Faith as an infant. "Our baby girl is now 9," she captioned the shot. "We love you so much precious precious girl. Happy birthday Faith!" She also shared a picture of the birthday girl's cake—decorated with luscious-looking chocolate icing and pink candles.

Urban and Kidman also share their older daughter, Sunday Rose, who is 11. Kidman additionally has two adult children with her ex-husband Tom Cruise, Connor and Isabella. The glimpse of baby Faith is extra special for fans, as Urban and Kidman are quite selective about sharing pictures of their kids, and therefore keep their images limited on social media.

Indeed, Kidman explained earlier this year to Vanity Fair that she hopes to keep Sunday and Faith off of social media for as long as she can. Citing the desire to establish "some sort of boundaries" for the children, she revealed that neither girl has a phone or Instagram account.

Instead of being sidetracked by technology, the girls have focused on other skills. Following in Dad's footsteps, both girls are interested in music: Faith plays violin and Sunday plays piano. Sunday has also expressed that she has an interest in acting, just like her famous mom.

See Keith Urban and Nicole Kidman Singing Together!

See Keith Urban and Nicole Kidman on the Red Carpet