Joanna Gaines just celebrated a major milestone and did it with those she's closest to.

Friends and family, including Joanna's two sisters, helped the Fixer Upper star celebrate her 40th birthday party with a sweet surprise party at Magnolia Table. All the Stevens women were there including their mom, Nan.

instagramView full post on Instagram

Want to know more about Joanna's sisters? Here are 10 fun facts:

1. There's three of them.

In addition to her younger sister Mary Kay, Joanna also has an older sister, Teresa Criswell—and they all definitely look related.

2. Mary Kay has the best nickname.

Mary Kay is affectionately called "Mikey" in Joanna's social media posts.

3. They all love plants.

These #plantladies can be seen grabbing greens from both Joanna's garden and Magnolia Market. And there were plenty of plants in Mary Kay's Fixer Upper reveal.

4. They're just as silly.

When they get together, these sisters are known to goof off, just like their kids. (It looks like they had a tad too much candy at the Sugar Factory in New York City!)

5. They're super supportive.

Even with all of Joanna's success from the show, there's nothing but love between these sisters.

6. They love big families.

Even though Joanna's family of four (soon to be five) kids is considered large, her sister Mary Kay has her beat with six kids.

7. Teresa runs a show of her own.

Older sister Teresa hosts an inspirational YouTube show called Let's Talk with Teresa Ann. She also writes lifestyle and faith-based posts at her blog Triumphant Victorious Reminders, and posts about healthy mother-daughter relationships on Instagram.

8. They were the cutest little girls.

Teresa frequently posts photos of the three of them as children on Instagram and they were absolutely adorable!

9. Joanna designed Mary Kay's home on an episode of Fixer Upper.

The Magnolia Market founder recently renovated a home for her younger sister's family, who's moving back to their hometown after being away for nine years. The new house is the perfect fit for the growing McCall clan—Mary Kay and her husband now have six children; they just welcomed a new baby.

"Today's house was my all time favorite #fixerupper," Joanna wrote in the post. "We got to reveal this house to my sweet sis and her family of seven (going on 8!). I can't contain the excitement-after nine years they are finally coming back to Waco!"

10. Joanna and Mary Kay were both pregnant at the same time.

The McCalls told Chip and Joanna they were expecting just before the house reveal on the episode, and the Gaineses announced their pregnancy right after the episode aired, which means both Joanna and Mary Kay were pregnant at the same time.

Headshot of Jessica Leigh Mattern
Jessica Leigh Mattern
Web Editor
Jessica Leigh Mattern is a web editor and writer who covers home, holiday, DIY, crafts, travel, and more lifestyle topics. Prior to working for Country Living, she wrote for several lifestyle and women’s magazines including Woman’s Day, Cosmopolitan, and Redbook