The spouses announced that they welcomed their second child on Nov. 28.
"Patrick 'Bronze' Lavon Mahomes III," Brittany and Patrick shared on Instagram as their son posed on a blanket. "11/28/22 7lbs 8oz."
Just one day earlier, Brittany was cheering on her husband as the Kansas City Chiefs faced the Los Angeles Rams. "Sterling said no to photos today, but she's still cute," she wrote on Instagram after hanging on the field with the couple's 21-month-old daughter. "#gochiefs." Patrick and his teammates would end up winning the game.
The couple's announcement post included photos of their daughter wearing a pink t-shirt with the words, "I have a secret to tell you," on it. In the snaps, Sterling was standing between her parents holding up a sign that said, "Baby sister duties coming soon."
In the past, Brittany has made it a point to take her fans on her motherhood journey, with the trainer regularly answering fan questions on her Instagram.
For the mom, she previously revealed that having Sterling as her "best friend" is one of her favorite parts about parenthood.
She makes me the happiest and even on my bad days I truly love being with her and doing things with her!" she shared on Instagram in April. "I love watching her grow up every day and start to be able to do things on her own!"
Britany and Patrick wed in a lavish ceremony on March 12 after getting engaged in September 2020. The NFL pro popped the question in a flower-filled box at Arrowhead Stadium.