Teen Mom star Catelynn Lowell shared a photo of her newborn daughter Nova Reign on Friday, Jan. 2

They're in baby heaven! Teen Mom star Catelynn Lowell shared a precious Instagram photo of her daughter Nova Reign on Friday, Jan. 2.

"You are already my world...I love you so much you have already changed me in so many ways," she wrote. "Mommy and daddy love you." In the pic, Nova is wrapped up in a white blanket and only revealing her little feet.

Lowell and fiance Tyler Baltierra, both 22, welcomed their second child on New Year's Day. (They documented putting their first daughter Carly, now 5, up for adoption on MTV's 16 and Pregnant in 2009.)

A photo posted by Catelynn Lowell (@catelynnmtv) on Jan 1, 2015 at 12:27pm PST

Nova weighed in at 6 lbs., 12 oz., and measured 19.5 inches. Baltierra was beside himself after her arrival, and gushed about his bride-to-be in an Instagram post.

"Momma Bear holding our little angel! Can't tell you the feeling of witnessing this," he wrote. "Look at my beautiful bride to be! That woman is beyond strong, caring, and selfless. Couldn't have asked for a better little family #Blessed #NewYearBaby #MyGirls #AreMyWorld."