The Grammy winner, 33, gave birth via a C-section at Cedars-Sinai Medical Center in Los Angeles.
Us broke news in February that the "Fighter" singer and Rutler — who got engaged just one month earlier — were expanding their family. In March, it was confirmed that they were expecting a little girl.
Aguilera was the guest of honor at a baby shower in L.A. on July 12. She glowed in a white Lattice maxi dress, donned a flower wreath headband and added a pop of color with a red lip. Rutler, on hand for the co-ed bash, sweetly kissed her growing belly during the festivities.
"It was very romantic with candles everywhere," an insider told Us at the time. "Christina looked so happy and excited." The Voice mentor's gal pals sipped on pink champagne and guests were treated to a very graphic cake, which showed a blonde woman giving birth.
Comfortable in her own skin, nude photos of Aguilera showing off her baby bump were released by V magazine on Aug. 1. "As a woman, I'm proud to embrace my body through all stages of life, staying fearless and confident in surrendering to the unknowns the future has in store," she told the mag. She also showed her appreciation for those involved with the photo shoot via Instagram. "[Thank you for] giving me the freedom to bare my soul & body at this incredible, magical, transition time in my life. #Grateful," she wrote on Aug. 1.
This is the second child for Aguilera and the first for Rutler. The powerhouse singer is already mom to 6-year-old son Max, whom she shares with ex-husband Jordan Bratman.