This family is growing faster than we can keep up with! Joanna Gaines' younger sister Mary Kay McCall just had a "beautiful baby girl," making the Fixer Upper star an aunt again! Joanna, who is pregnant herself, shared sweet photos of Mom and Baby on her Instagram.

"My sister had her beautiful baby girl! #motherofsix #butshelooks16 ?," she captioned the photo. Joanna also posted photos of her older sister, Teresa Criswell, and mom, Nan Stevens, posing with the newborn. No word yet on her name, but she is a cutie!

This happy news comes just two days after Joanna and her husband Chip Gaines, 43, announced that they are expecting baby no. 5! And considering Mary Kay (or “Mikey”, as she’s known to the family) and her husband David already had five children of their own — this new bundle of joy makes six! — Joanna has the perfect person to ask for advice when it comes to raising a big family.

Fans recently met Mary Kay in an episode of Fixer Upper where Chip and Joanna took on their "all-time favorite" project — making over a home for Mary Kay and her family after she decided to move back to Waco, Texas, after nine years. In the same episode, Chip and Joanna revealed their big baby news.

“Gaines party of 7… (If you’re still confused… WE ARE PREGNANT)," Chip posted on his Instagram.

Chip and Joanna are already parents to Drake, 12, Ella, 11, Duke, 9, and Emmie Kay, 7. Congrats to both growing families!