This country music family has just gotten a little bit bigger: Singer-songwriter Krystal Keith, who is also the daughter of country icon Toby Keith, welcomed her second child on Tuesday (Jan. 29).

According to a post on Instagram, Kirby Kaye Sandubrae was born on Tuesday morning, weighing 7 lbs., 14 oz. She is Keith and husband Andrew Sandubrae's second daughter; their first child, Hensley Jack Sandubrae, was born in October of 2015.

"When you thought you had loved as big as you ever could. And then in a single moment, the size of that love doubles," writes Keith. "We are happy and healthy. Hensley Jack is the best big sister and Drew is way outnumbered with a house full of girls and wouldn't change a thing."

Indeed, Hensley seems thrilled to have a younger sibling. On Instagram, Keith shared a photo of her first child "report[ing] for duty" at the hospital, decked out in "Big Sister" scrubs and a stethoscope. She's also shared a photo of the two little girls cuddling.

The Sandubraes originally announced their second pregnancy in July of 2018. The couple enlisted the help of daughter Hensley to share the exciting news via an Instagram video: In the post, wearing a blue "Big Sister" T-shirt and carrying a baby doll, Hensley announces, "Mommy has a baby in her belly!" and, "Hey guys, I'm gonna be a big sister!"

The oldest daughter of Toby Keith and his wife Tricia, Krystal Keith has been married to Sandubrae since 2010. The new baby is the "How Do You Like Me Now?!" star's fourth grandchild in total, as his adopted daughter Shelley also has two children.

Just before announcing her pregnancy, earlier in July, Keith released a new five-song EP, Boulder. that project follows her studio debut, Whiskey & Lace, which came out in 2013.

Meet the Country Babies Born in 2018