The 27-year-old former "Laguna Beach: The Real Orange County" star announced her successful delivery by posting a message on Twitter, "Welcome Jaxon Wyatt Cutler 7lbs 11oz 5/7/14 ❤️."
The post carried a link to another one Cavallari made on Instagram.
While the Instagram post had the same message, it was accompanied by a picture of a pair of booties with Cavallari's hospital ID wrapped around them and placed on top of a baby bonnet.
The new bundle of joy, a baby boy, was christened with the name "Jaxon Wyatt" and follows older brother Camden Jack, 21 months old, who was staying at home.
Regarding the now two kids she has and their relationship, Cavallari once said what most second-time moms feel at one point or another; that the change in family dynamic a new baby brings might make the older child feel left out, People reported.
"We try to tell him there's a baby inside Mommy's belly. He doesn't really understand that," she shares. "We'll be like, ‘Camden, do you want to be a big brother?' and he'll shake his head no," she told reporters.
Cavallari said she just hoped that based on his current actions, Camden would be a great brother once everything gets carried out.
"He's really a sweet little boy," she explained. "When I have play dates, he's really more interested in the babies than the older boys and girls. Any time a baby comes over, he's really concerned about the baby and wants to hug it and give it kisses."
"I'm nervous," she admitted. "I don't want him to feel like he's being replaced. I know the first few months are going to be hard when I'm breastfeeding all the time. We're just going to try to be so careful to make sure he's still getting a lot of attention, knows he's still extremely loved and this baby is in no way taking his spot."
On the other hand, the fact that Jaxon Wyatt is a second pregnancy meant things were easier for the actress and her 31-year-old husband.
"I got him a new blanket and a little rattle and a couple of little things, but overall, I haven't had to get anything," she explained.
"It's been really easy. The second time around, you know exactly what to expect and we're just ready.