Christina Aguilera Shares Rare Photos of Daughter Summer on Her 9th Birthday

Christina Aguilera shares daughter Summer Rain with fiancé Matt Rutler.

Christina Aguilera is looking back on her "ultimate accomplishment" as she celebrates her 9-year-old daughter Summer Rain's birthday. The 42-year-old "Beautiful" singer took to Instagram Wednesday to celebrate her youngest child's big day, sharing rare photos of Summer on stage with her during a show and rocking out on a drum set.

"Happy 9th birthday to our sweet Summer Rain," the Grammy-winning singer captioned the post, which features photos of Summer seemingly taken during Aguilera's first Israel show on Aug. 10 at Live Park. "Today I find myself reflecting on how fast time has gone by. These 9 years have been filled with boundless love, heartwarming hugs, staying up too late, Disney adventures, and most recently, the joy of gracing the stage alongside you."

The birthday post also included a video of the "Genie in a Bottle" singer hugging her smiling daughter and dancing with her on stage while dancers perform behind the two. "Every day, I thank the universe for gifting me the privilege of being your momma, a role that stands as my ultimate accomplishment," Aguilera concluded. "Witnessing the remarkable young woman you are evolving into fills me with immense pride. Mommy loves you so much!"

Aguilera shares Summer with her fiancé, Matt Rutler, having welcomed the little girl in 2014 just months after getting engaged to Rutler on Valentine's Day 2014. Summer is Rutler's first child. Aguilera also shares her 15-year-old son Max Liron with her ex-husband, music producer Jordan Bratman. Rutler also shared a loving birthday message for his daughter, posting on Instagram a video of Summer going on stage at her mom's show alongside another video of the father and daughter looking out at the sunset. "Happy 9th Birthday to our little sunshine :)" he wrote in the caption.

In a recent appearance on Call Her Daddy, Aguilera described her type of man as a "guys next door" kind, explaining that she never felt comfortable dating other celebrities. "I didn't really have time for that. I always went for things that I would feel safe about," she explained, adding, "My life is hectic enough, and this is a very narcissistic industry. My anxieties couldn't maybe take somebody that did the exact same thing I did. I know how this goes. I'm too vulnerable for this. I'm too sensitive to be so paranoid."