Brittany Mahomes is sharing another peek at her baby girl. On Thursday, Feb. 20, the mom of three, 29, shared a post on her Instagram as she celebrated her daughter Sterling Skye's 4th birthday, which included a sweet photo of Sterling with her baby sister Golden Raye. In the snap, Sterling can be seen wearing a pink long-sleeve T-shirt and holding her baby sister, who had a white cap on and a pink onesie. Sterling feeds her sister a bottle as another person out of frame reaches out to help support Golden. Later on her Instagram Stories, Brittany shared a Reel of Sterling pushing Golden's stroller, staring off into the distance as she rocked back and forth. "The best big sister 🥹," she wrote across the video. Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories. Brittany shares her daughters Sterling and Golden, as well as son Patrick "Bronze" Lavon III, 2, with husband Patrick Mahomes. On Jan. 12, the Kansas City Chiefs current co-owner and Kansas City Chiefs quarterback welcomed their third baby, announcing the exciting news on Instagram with a black-and-white photo. In the photo, Brittany and Patrick could be seen holding their baby daughter's feet above a wooden sign that read her name. "•Golden Raye Mahomes• 1/12/25🎀✨," they wrote in the caption of their joint post. Shortly after welcoming her daughter, Brittany shared an adorable clip on her Instagram Stories, showing Golden's little feet. The onesie that she was wearing had footballs printed on her legs and both feet — a sweet nod to her father, Patrick. "The cutest little feet 🥹" wrote the former soccer player in text over the video. Ahead of welcoming Golden, Brittany spoke with PEOPLE about her daughter's nursery, saying that she was "feeling very ready" and "excited about becoming a family of 5." Even her older kids were ready to be big siblings. "They're both excited to have a baby sister — even though Bronze is still a little too young to fully understand, he can't wait," Brittany said at the time. "Sterling is the best big sister already and has been loving going into the baby's room to play with the new toys." The famous couple shared that while they were able to choose a name for their daughter "pretty quickly," they struggled for a minute on the middle name — despite Sterling's suggestions. "Sterling has thrown out names," Brittany revealed. "She wants us to name her Elsa, but we won't be doing that."