It's (just) a girl! Gwen Stefani helps a Norwalk mom with her gender reveal

Count on "Just a Girl" singer Gwen Stefani to announce you're expecting a daughter — as a Norwalk mom-to-be just did.

The Grammy-winning "Sweet Escape" singer helped fan Vanessa Venegas and her loved ones learn she is expecting a baby girl during Stefani's concert at the Honda Center in Anaheim over the weekend. An Instagram video shared Sunday by radio station KOST-103.5 FM recalled the moment.

Stefani, wearing a sparking, silver ensemble; accepted the letter and said, "I've never done this before." As fans cheered, the singer knelt onstage to open the envelope, joking, "[Is] it like a long note or something?"

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After catching a quick glimpse at the piece of paper, Stefani smiled and stood up. "Just a girl," she exclaimed to her fans.

"Are you serious? You didn't know?," the "Voice" personality added.

Venegas' gender reveal came together with the help of KOST and veteran radio personality Ellen K. According to KOST, Venegas called into the station on Sept. 1 sharing her plans to attend Stefani's Saturday concert.

"I'm ready to reveal the gender of my baby and my idea is to have my idol, Gwen Stefani, reveal the gender," she told Ellen K. "And I need your help to get her attention."

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Immediately, Ellen K said she and her team were "on board" with the plan and began planning how Stefani would get hold of the baby's gender. "We're on your team, we are going to try to get this done, Vanessa," the host said. Clearly, the KOST team delivered.

Saturday's concert held meaning for more than just Venegas, as Stefani celebrated the "incredible hometown show" in a Sunday Instagram post. The singer, who grew up in Anaheim, shared a video of her time onstage rehearsing and performing for the venue's packed audience.

"We've built decades of love + memories together, and getting the opportunity to share that with u at @hondacenter for the 9th time was nothing short of a dream," she captioned the video.

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Stefani's performance helped the Honda Center celebrate its 30th anniversary. The venue reciprocated the singer's love on Instagram, remembering the Saturday concert as the "BEST. 30TH. BIRTHDAY. PARTY. EVER."

"So much love for our hometown girl @gwenstefani, our hardworking team, and the incredible fans who made this an unforgettable night," the arena's post said. "ANAHEIM! Let’s keep on dancin’ for the next thirty years. #HondaCenter30"

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This story originally appeared in Los Angeles Times.